darc vmr update command incorrectly applies a newly added patch with the `--reverse` option

[ViktorHofer]

This happened in dotnet/installer#19634

We added a new patch for the roslyn repo but the patch always got applied with the --reverse option:

git -C src/roslyn apply --cached --ignore-space-change --reverse --directory "src/roslyn" src/installer/src/SourceBuild/patches/roslyn/0001-Avoid-ambiguous-call-site.patch

(The above command is from a local run in which I tried to reproduce this)