TransformResolutionCache test cleanup

[Wumpf]

Just some minor, mostly non-functional test cleanup, wrapping up things I had lying around.

[github-actions]

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Result	Commit	Link	Manifest
✅	4911244	https://rerun.io/viewer/pr/12124	+nightly +main

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[Copilot]

Pull request overview

This PR performs minor, mostly non-functional cleanup of tests in the TransformResolutionCache module. The changes improve code readability and maintainability by reorganizing imports, refactoring repetitive test assertions into loops, and simplifying method calls.

• Simplified imports by removing unused items and directly importing commonly-used types
• Refactored repetitive test assertions into loop-based structures for better maintainability
• Cleaned up method call formatting by removing unnecessary line breaks

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[Copilot]

The error message incorrectly refers to 'before/after' but only includes the 'before' value. Update the message to include both values: \"Expected cache size to decrease after GC (before: {num_bytes_before_gc} bytes, after: {num_bytes_after_gc} bytes)\"

Suggested change

	"Expected cache size to decrease after GC (before/after: {num_bytes_before_gc} bytes)"
	"Expected cache size to decrease after GC (before: {num_bytes_before_gc} bytes, after: {num_bytes_after_gc} bytes)"