chore: still keep ctx in git.Repository struct for cat-file batch command (#38684)

Unfortunately, we can't completely remove the ctx from git.Repository,
because the CatFileBatch still heavily depends on a parent context.

If we remove the Repository ctx, the CatFileBatch will become a mess and
create a lot of unnecessary git processes.

http://localhost:3000/-/admin/monitor/perftrace

* Before: open a repo home, dozens of git processes (duplicate cat-file)
* After: only a few (no duplicate cat-file)

routers/web/repo/setting/lfs.go

@@ -121,7 +121,7 @@ func LFSLocks(ctx *context.Context) {
 		return
 	}
 
-	gitRepo, err := git.OpenRepositoryLocal(tmpBasePath)
+	gitRepo, err := git.OpenRepositoryLocal(ctx, tmpBasePath)
 	if err != nil {
 		log.Error("Unable to open temporary repository: %s (%v)", tmpBasePath, err)
 		ctx.ServerError("LFSLocks", fmt.Errorf("failed to open new temporary repository in: %s %w", tmpBasePath, err))