[lmalloc]

Summary

This small PR polishes native_decide statements and an outdated structural invariant used within zkVMs. More in details, it:

• Replaces the native_decide tactic within h_earlyStop of FRIConfig with a kernel-clean equivalent;
• Removes unnecessary native_decide tactics in determining field consistency of DeepAliCfg within Soundcalc/ZkVM/Zisk.lean;
• Removes the field consistency invariant at zkVM level. Following #37, soundcalc supports an optional override of the zkVM-field at circuit level.