Add '--' to 'git rev-list' to disambiguate branch name from path

[efussi]

• PR Description

When deleting a local branch that has the same name as a file known to git (say test), a popup with the following error is shown:

fatal: ambiguous argument 'test': both revision and filename
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]' 

The command log reveals this:

git rev-list --max-count=1 test ^HEAD ^refs/heads/main

• Please check if the PR fulfills these requirements

• Cheatsheets are up-to-date (run go generate ./...)
• Code has been formatted (see here)
• Tests have been added/updated (see here for the integration test guide)
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• Docs have been updated if necessary
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[efussi]

When adding the double dash, it works:

[stefanhaller]

LGTM, thanks. We fixed similar issues in other places before, and I suppose we still might have more of them in other places, but I guess it's ok to fix them when we come across them.