Rollup merge of #93469 - compiler-errors:issue-93450, r=estebank

Skip pointing out ambiguous impls in alloc/std crates too in inference errors

This generalizes the logic in `annotate_source_of_ambiguity` to skip printing ambiguity errors traits in `alloc` and `std` as well, not just `core`.

While this does spot-fix the issue mentioned below, it would be nicer to generalize this logic, for example to detect when the trait predicate's `self_ty` has any numerical inference variables. Is it worthwhile to scrap this solution for one like that?

Fixes #93450

r? `@estebank`
feel free to reassign

compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs

@@ -1954,7 +1954,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> {
 
         if self.is_tainted_by_errors()
             && crate_names.len() == 1
-            && crate_names[0] == "`core`"
+            && ["`core`", "`alloc`", "`std`"].contains(&crate_names[0].as_str())
             && spans.len() == 0
         {
             // Avoid complaining about other inference issues for expressions like