project: disable auto-gc on fetch for projects with clone-depth=1

This prevents GC hangs on repos with large binaries by skipping implicit
GC during network fetch, using clone-depth=1 as a heuristic.

Bug: 379111283
Change-Id: I977bf8cd521b11e37eba7ebc9f62120f2bbaf760
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/533802
Tested-by: Gavin Mak <gavinmak@google.com>
Commit-Queue: Gavin Mak <gavinmak@google.com>
Reviewed-by: Mike Frysinger <vapier@google.com>

project.py

@@ -2572,6 +2572,16 @@ class Project:
             if os.path.exists(os.path.join(self.gitdir, "shallow")):
                 cmd.append("--depth=2147483647")
 
+        # Use clone-depth="1" as a heuristic for repositories containing
+        # large binaries and disable auto GC to prevent potential hangs.
+        # Check the configured depth because the `depth` argument might be None
+        # if REPO_ALLOW_SHALLOW=0 converted it to a partial clone.
+        effective_depth = (
+            self.clone_depth or self.manifest.manifestProject.depth
+        )
+        if effective_depth == 1:
+            cmd.append("--no-auto-gc")
+
         if not verbose:
             cmd.append("--quiet")
         if not quiet and sys.stdout.isatty():