Give non-existent files a durability of at least Medium

[MichaReiser]

Summary

Partially addresses #13169

The solution isn't ideal, but our problem is that the module resolves first queries if certain first-party files exist and only then resolves the standard library modules. The issue with that is that any query that depends on a resolved standard library module now depends on non-existing LOW durability files, negating the benefit of giving standard library files high durability.

This PR changes the durability of the File::status to at least medium. This is still not perfect because it means that all standard library queries that depend on module resolution still have a MEDIUM durability instead of HIGH, but it's better than what we have today, and it should allow Salsa to take the "fast-incremental path" more often.

This possibly helps with #14024

Test Plan

See benchmarks

[codspeed-hq]

CodSpeed Performance Report

Merging #14034 will improve performances by 7.43%

_{Comparing micha/file-status-durability (c485dce) with main (48fa839)}

Summary

⚡ 1 improvements
✅ 31 untouched benchmarks

Benchmarks breakdown

	Benchmark	main	micha/file-status-durability	Change
⚡	red_knot_check_file[incremental]	4.6 ms	4.3 ms	+7.43%

[github-actions]

ruff-ecosystem results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

✅ ecosystem check detected no linter changes.

[carljm]

So just to make sure I understand the effect here: module resolutions that only use typeshed files (but first have to verify that some first-party paths don't exist) will now be MEDIUM instead of LOW durability, meaning we won't have to re-resolve those paths on any change to a first-party file. Adding a previously-not-existent first-party file will count as a MEDIUM durability input change, and cause those queries to have to re-execute. Is that an accurate summary?

Looks good!

[MichaReiser]

So just to make sure I understand the effect here: module resolutions that only use typeshed files (but first have to verify that some first-party paths don't exist) will now be MEDIUM instead of LOW durability, meaning we won't have to re-resolve those paths on any change to a first-party file. Adding a previously-not-existent first-party file will count as a MEDIUM durability input change, and cause those queries to have to re-execute. Is that an accurate summary?

Looks good!

Yes, that's a perfect summary.