pickman: Fetch before force-push to update tracking refs

When using --force-with-lease with an HTTPS URL (instead of a remote
name), git cannot find the tracking refs automatically. This causes
"stale info" errors when the local tracking ref is out of date.

Fix by fetching the branch first to update the tracking ref before
pushing.

Co-developed-by: Claude <noreply@anthropic.com>
Signed-off-by: Simon Glass <simon.glass@canonical.com>

tools/pickman/gitlab_api.py

@@ -194,11 +194,17 @@ def push_branch(remote, branch, force=False, skip_ci=True):
         push_url = get_push_url(remote)
         push_target = push_url if push_url else remote
 
+        # When using --force-with-lease with an HTTPS URL (not remote name),
+        # git can't find tracking refs automatically. Fetch first to update
+        # the tracking ref, then explicitly specify which ref to check.
+        if force and push_url:
+            command.output('git', 'fetch', remote, branch)
+
         args = ['git', 'push', '-u']
         if skip_ci:
             args.extend(['-o', 'ci.skip'])
         if force:
-            args.append('--force-with-lease')
+            args.append(f'--force-with-lease=refs/remotes/{remote}/{branch}')
         args.extend([push_target, f'HEAD:{branch}'])
         command.output(*args)
         return True