Should run git reset --hard on checking out to different branches

[JounQin]

For example, when master is not ready and I add a gitsubmodule in a PR, currently this action will always fail the submodule contains some files which are expected to be ignored, but when this action checks out to main branch, the submodule is still there, so maybe git reset --hard may help.

/usr/bin/git checkout -f main
warning: unable to rmdir 'DOMPurify': Directory not empty