Auto merge of #115304 - Enselic:trailing-gt, r=cjgillot

Allow file names to end with '>'

The [`rustc_span::FileName`](https://doc.rust-lang.org/stable/nightly-rustc/rustc_span/enum.FileName.html) enum already differentiates between real files and "fake" files such as `<anon>`. We do not need to artificially forbid real file names from ending in `>`.

Closes #73419

Author: bors