rustfmt only sometimes detects path-based nested config
files (probably some kind of race?), so my users folder uses a
separate formatting check for rustfmt to avoid flaky CI. Enough flakes
around already ...
Change-Id: Ifd862f9974f071b3a256643dd8e56c019116156a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5242
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
