fix: refuse to trim rlibs without a sibling .rmeta

[coredoesdev]

Fixes a Rust distributed compilation failure where .rlibs lacking a sibling .rmeta are trimmed to a metadata-only stub that the remote rustc cannot read, leading to extern location for <crate> does not exist errors. Similar mode of failure to https://bugzilla.mozilla.org/show_bug.cgi?id=1760743.

Reproducible while trying to compile tracing_wasm from a Linux client.

Extends the fix from 1760743: updates can_trim_this to refuse to trim rlibs that do not have associated metadata files (so that something is sent to the remote rustc). Resolves the tracing_wasm compilation failures in testing on my team's cluster.

[sylvestre]

please add a test to make sure we don't regress in the future

[codecov-commenter]

Codecov Report

❌ Patch coverage is 66.66667% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 60.69%. Comparing base (b81fdbb) to head (9ede862).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
src/compiler/rust.rs	66.66%	1 Missing ⚠️

❗ There is a different number of reports uploaded between BASE (b81fdbb) and HEAD (9ede862). Click for more details.

HEAD has 6 uploads less than BASE

Flag	BASE (b81fdbb)	HEAD (9ede862)
	10	4

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #2685       +/-   ##
===========================================
- Coverage   73.58%   60.69%   -12.90%     
===========================================
  Files          70       69        -1     
  Lines       38220    37475      -745     
===========================================
- Hits        28125    22746     -5379     
- Misses      10095    14729     +4634     

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