chore: perf lint

[cpcloud]

Add "PERF" lints to the ruff config. For our current kernel launch benchmarks there is no change. Most of the changes here would not be incredibly impactful on their own.

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[cpcloud]

/ok to test

[greptile-apps]

Greptile Summary

This PR adds PERF lints to the ruff configuration and applies the resulting auto-fixes across the codebase. The changes are primarily mechanical performance improvements.

Key Changes

• Added extend-select = ["PERF"] to ruff configuration in pyproject.toml
• Excluded test files and simulator code from PERF lints to avoid unnecessary churn
• Applied automatic PERF lint fixes across 29 code files

Types of Performance Improvements

• Converted loops with .append() to list/dict comprehensions (more Pythonic and efficient)
• Replaced indexed loops with direct iteration (e.g., for item in items instead of for i in range(len(items)))
• Changed loops with .append() to .extend() calls for batch operations
• Used walrus operator (:=) to eliminate try/except AttributeError patterns
• Removed unused loop variables (e.g., for k, v in dict.items() → for v in dict.values() when k is unused)
• Added # noqa: PERF203 comments for legitimate exception handling patterns that shouldn't use walrus operator

All changes are automated refactorings that preserve existing behavior while following Python performance best practices.

Confidence Score: 5/5

• This PR is safe to merge - all changes are automated lint fixes that preserve behavior
• The changes are entirely automated refactorings from enabling PERF lints. The transformations are well-established Python idioms (comprehensions, walrus operator, direct iteration) that preserve semantics. No logical changes were made, only syntactic improvements. The author appropriately added noqa comments where exception handling patterns should remain unchanged.
• No files require special attention

Important Files Changed

Filename	Overview
pyproject.toml	Added PERF lints to ruff config with exclusions for test and simulator files
numba_cuda/numba/cuda/core/controlflow.py	Replaced loop appends with extend() calls for better performance
numba_cuda/numba/cuda/cudadrv/driver.py	Used walrus operator to eliminate try/except AttributeError pattern, added noqa: PERF203 for legitimate exception handling
numba_cuda/numba/cuda/core/ir_utils.py	Converted multiple loops to dict/list comprehensions, replaced loop iteration over unused keys with .keys() and .values()
numba_cuda/numba/cuda/core/interpreter.py	Multiple perf improvements: removed unused loop variables, converted loops to comprehensions and dict updates
numba_cuda/numba/cuda/core/base.py	Converted loop to dict comprehension and used walrus operator for attribute checking

[rparolin]

@gmarkall for visibility