Stabilize inline CodeLens test cleanup on Windows (#1913)

## Summary

- retry transient Windows filesystem locks when removing the inline
CodeLens integration workspace
- keep cleanup failures visible after a bounded retry window
- document the Windows integration-test cleanup pattern

## Validation

- `npm run lint`
- `npm run compile-tests`
- `npm run unittest` (`2812 passing`, `7 pending`)
- `npm run compile`
- targeted CodeLens integration suite passed once, then 10 consecutive
Windows stress runs passed with no leftover temporary workspaces
- deterministic Windows probe reproduced `EBUSY` without retries and
verified the bounded retry removes the held directory
- full integration run passed the CodeLens suite; an unrelated
environment-creation test timed out

Fixes #1911

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

Author: StellaHuang95

.github/instructions/testing-workflow.instructions.md

@@ -616,3 +616,4 @@ envConfig.inspect
 - **pet binary is required for environment manager registration**: The smoke/E2E/integration tests require the `pet` binary from `microsoft/python-environment-tools` to be built and placed in `python-env-tools/bin/`. Without it, `waitForApiReady()` will timeout because managers never register. CI must build pet from source using `cargo build --release --package pet` (2)
 - **Check exact project registration with `getPythonProjects()`**: `getPythonProject(uri)` can return a containing parent project, so it cannot prove that a nested project was registered or unregistered (1)
 - **Use controlled fixture providers for package lifecycle integration tests**: Discovering an existing Conda environment does not guarantee API quick-create can succeed. Use `createEnvironmentFixture()` so creation prerequisites and cleanup are deterministic (1)
+- **Retry Windows integration-test cleanup at the filesystem operation, not the suite**: After closing VS Code editors, use bounded `fs.rm(..., { recursive: true, force: true, maxRetries, retryDelay })` for temporary workspaces because Windows can briefly return `EBUSY`; keep final failures visible instead of adding sleeps or Mocha retries (1)

src/test/integration/inlineScriptCodeLens.integration.test.ts

@@ -61,7 +61,12 @@ inlineScriptCodeLensSuite('Integration: Live inline script CodeLens', function (
     });
 
     suiteTeardown(async () => {
-        await fs.rm(root, { recursive: true, force: true });
+        await fs.rm(root, {
+            recursive: true,
+            force: true,
+            maxRetries: 5,
+            retryDelay: 100,
+        });
     });
 
     async function lenses(): Promise<vscode.CodeLens[]> {