Auto merge of #108359 - Zoxc:side-effects-tweak, r=cjgillot

Avoid code generation for ThinVec<Diagnostic>'s destructor in the query system

This avoids 2 instances of the destructor of `ThinVec<Diagnostic>` from being included in `execute_job`. It also outlines the cold branch in `store_side_effects` / `store_side_effects_for_anon_node`.