refactor: make git package handle all git operations (#38543)

before: gitrepo vs git packages
after: git package fully handle all git operations

by the way, use `WithRepo(repo)` instead of `WithDir(repo.Path)` to hide
path details.

benefits:

1. remove all unnecessary wrappers, developers no need to struggle with
"which package should be used"
2. simplify code, RepositoryFacade can (will) be used everywhere, all
"path" details are (will be) hidden

modules/git/ref.go

@@ -8,6 +8,7 @@ import (
 	"regexp"
 	"strings"
 
+	"gitea.dev/modules/git/gitcmd"
 	"gitea.dev/modules/setting"
 	"gitea.dev/modules/util"
 )
@@ -242,3 +243,11 @@ func ParseRefSuffix(ref string) (refName, refSuffix string) {
 	}
 	return ref[:suffixIdx], ref[suffixIdx:]
 }
+
+func UpdateRef(ctx context.Context, repo RepositoryFacade, refName, newCommitID string) error {
+	return gitcmd.NewCommand("update-ref").AddDynamicArguments(refName, newCommitID).WithRepo(repo).Run(ctx)
+}
+
+func RemoveRef(ctx context.Context, repo RepositoryFacade, refName string) error {
+	return gitcmd.NewCommand("update-ref", "--no-deref", "-d").AddDynamicArguments(refName).WithRepo(repo).Run(ctx)
+}