Auto merge of rust-lang#148188 - Muscraft:annotate-snippets-default-on-nightly, r=estebank

feat: Use annotate-snippets by default on nightly

This PR switches the default renderer to use `annotate-snippets` on nightly, but does not affect stable. This is part of the ongoing effort to use `annotate-snippets` to render all diagnostics.

[MCP](rust-lang/compiler-team#937)

Note: This contains the test change from rust-lang#148004, without the change to the default emitter.

rust-lang#59346
rust-lang/rust-project-goals#123

r? `@davidtwco`

Author: bors