Optimize some SemanticModel methods

[AlexWaygood]

No description provided.

[github-actions]

ruff-ecosystem results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

✅ ecosystem check detected no linter changes.

[AlexWaygood]

The premise of this PR is that in Python, a statement can contain a statement, an expression can contain an expression, and a statement can contain an expression -- but an expression cannot contain a statement. As such, for various methods that iterate through all "parent expression nodes" in the AST, we can stop as soon as we hit a statement node, since we know that there can be no parent expression nodes of that statement node.

It seems like this has no impact on the Codspeed microbenchmarks, but it still feels to me like the "right" thing to do regardless, if you consider Python's semantics... anyway, I'll let others judge whether it's worth it!

[codspeed-hq]

CodSpeed Performance Report

Merging #13091 will improve performances by 5.32%

_{Comparing optimize-current-exprs (2da0cb6) with main (f50f873)}

Summary

⚡ 1 improvements
✅ 31 untouched benchmarks

Benchmarks breakdown

	Benchmark	main	optimize-current-exprs	Change
⚡	linter/all-rules[numpy/globals.py]	767.8 µs	729 µs	+5.32%