Remove capability tests that duplicate existing package-manager routing coverage

getPackageManagerCapability resolves its manager via the same
PythonEnvironmentManagers.getPackageManager routing already used by
getPackages/managePackages/refreshPackages, and already exhaustively
tested in packageManager.api.unit.test.ts. Several tests in
extensionApi.capabilities.unit.test.ts re-exercised that same
pre-existing routing (project inference, ambiguous/missing project
fallback prevention) through the new capability entry point without
testing anything specific to capability advertisement:

- 'queries the preferred non-project package provider without project
  inference' duplicated the project-independent manager tests.
- 'environment routing infers a unique project and selects its
  different configured provider' duplicated the unique-project
  resolution test.
- 'does not fall back to a project-aware root with 0/2 matching
  projects' duplicated the ambiguous/missing project tests.

Simplified 'a missing configured provider cannot fall back to the
preferred root' to only cover the explicit-project path, which is
genuinely new (no other package method accepts an explicit project
override), dropping the environment-only variant that duplicated the
existing undefined-manager-id lookup behavior. Removed the now-unused
getLastKnownEnvironment stub that only the deleted tests relied on.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: edvilme

src/test/extensionApi.capabilities.unit.test.ts

@@ -44,7 +44,6 @@ suite('PythonEnvironmentApiImpl - capability queries', () => {
     let disposables: Disposable[];
     let getExtension: sinon.SinonStub;
     let configuredPackage: sinon.SinonStub;
-    let selectedEnvironment: sinon.SinonStub;
     let envProbe: sinon.SinonStub<[CapabilityContext], Promise<Support>>;
     let pkgProbe: sinon.SinonStub<[CapabilityContext], Promise<Support>>;
     let scopedProbe: sinon.SinonStub<[CapabilityContext], Promise<Support>>;
@@ -69,7 +68,6 @@ suite('PythonEnvironmentApiImpl - capability queries', () => {
             onDidChangeProjects: projectChanges.event,
         } as unknown as PythonProjectManager;
         managers = new PythonEnvironmentManagers(projectManager);
-        selectedEnvironment = sinon.stub(managers, 'getLastKnownEnvironment').returns(environment);
         type ApiArgs = ConstructorParameters<typeof PythonEnvironmentApiImpl>;
         api = new PythonEnvironmentApiImpl(
             managers,
@@ -170,15 +168,6 @@ suite('PythonEnvironmentApiImpl - capability queries', () => {
         await assert.rejects(api.getPackageManagerCapability(environment, 'packages.list'), (error) => error === failure);
     });
 
-    test('queries the preferred non-project package provider without project inference', async () => {
-        projects = [];
-        registerOwner();
-        registerPackages();
-        assert.strictEqual((await api.getPackageManagerCapability(environment, 'packages.list')).supported, true);
-        assert.strictEqual(pkgProbe.firstCall.args[0].environment, environment);
-        assert.ok(selectedEnvironment.notCalled);
-    });
-
     test('explicit project selects its configured scoped provider without a registered owner', async () => {
         configuredPackage.returns(`${extensionId}:configured`);
         const create = registerPackages(true, 'configured');
@@ -189,18 +178,6 @@ suite('PythonEnvironmentApiImpl - capability queries', () => {
         assert.ok(configuredPackage.calledWithExactly(projectManager, project.uri));
     });
 
-    test('environment routing infers a unique project and selects its different configured provider', async () => {
-        registerOwner();
-        const preferredFactory = registerPackages(true);
-        configuredPackage.returns(`${extensionId}:configured`);
-        const configuredFactory = registerPackages(true, 'configured');
-        assert.strictEqual(await api.getPackageManagerCapability(environment, 'packages.list'), scopedSupport);
-        assert.ok(preferredFactory?.notCalled);
-        assert.ok(configuredFactory?.calledOnceWithExactly(project));
-        assert.ok(scopedProbe.calledOnceWithExactly({ environment, project }));
-        assert.ok(pkgProbe.notCalled);
-    });
-
     test('environment-only package queries are unavailable until both providers register', async () => {
         const support = await api.getPackageManagerCapability(environment, 'packages.list');
         assert.ok(!support.supported && support.reason.length > 0);
@@ -213,21 +190,6 @@ suite('PythonEnvironmentApiImpl - capability queries', () => {
         assert.strictEqual((await api.getPackageManagerCapability(environment, 'packages.list')).supported, true);
     });
 
-    for (const matchingProjects of [0, 2]) {
-        test(`does not fall back to a project-aware root with ${matchingProjects} matching projects`, async () => {
-            projects =
-                matchingProjects === 0
-                    ? []
-                    : [project, { name: 'second', uri: Uri.joinPath(Uri.file(process.cwd()), 'second') }];
-            registerOwner();
-            const create = registerPackages(true);
-            const support = await api.getPackageManagerCapability(environment, 'packages.list');
-            assert.ok(!support.supported && support.reason.length > 0);
-            assert.ok(create?.notCalled);
-            assert.ok(pkgProbe.notCalled);
-        });
-    }
-
     test('an untracked explicit project never probes a project-aware root', async () => {
         projects = [];
         registerPackages(true);
@@ -239,10 +201,8 @@ suite('PythonEnvironmentApiImpl - capability queries', () => {
         registerOwner();
         const create = registerPackages(true);
         configuredPackage.returns(`${extensionId}:missing`);
-        for (const explicitProject of [undefined, project]) {
-            const support = await api.getPackageManagerCapability(environment, 'packages.list', explicitProject);
-            assert.ok(!support.supported && support.reason.length > 0);
-        }
+        const support = await api.getPackageManagerCapability(environment, 'packages.list', project);
+        assert.ok(!support.supported && support.reason.length > 0);
         assert.ok(create?.notCalled);
         assert.ok(pkgProbe.notCalled);
     });