Auto merge of #70931 - Dylan-DPC:rollup-f8orcao, r=Dylan-DPC

Auto merge of #70931 - Dylan-DPC:rollup-f8orcao, r=Dylan-DPC

Rollup of 9 pull requests

Successful merges:

 - #70789 (remove false positives of unused_braces)
 - #70847 (ci: move /var/lib/docker to /mnt on GHA)
 - #70850 (BTreeMap first last proposal tweaks)
 - #70876 (Use a `SmallVec` for `Cache::predecessors`.)
 - #70883 (Clean up E0507 explanation)
 - #70892 (wf: refactor `compute_trait_ref`)
 - #70914 (Corrects a typo in rustdoc documentation.)
 - #70915 (Remove unnecessary TypeFlags::NOMINAL_FLAGS)
 - #70927 (Clean up E0510 explanation)

Failed merges:

r? @ghost