scripts: Fix delete-remote-branches script

We were deleting patch branches, oops.

scripts/delete-remote-branches.sh

@@ -2,6 +2,18 @@
 # Delete all remote branches that don't have a local copy.
 
 remote="rad"
+remote_branches="$(git for-each-ref --format='%(refname:short)' refs/remotes/rad)"
+
+# Check that a branch isn't a remote tracking branch.
+is_remote_branch() {
+  for remote_branch in $remote_branches; do
+    # Remove the "rad/" prefix
+    if [ "$1" = "${remote_branch#rad/}" ]; then
+      return 0
+    fi
+  done
+  return 1
+}
 
 # Iterate over all remote branches.
 for branch in $(git branch -r --format "%(refname:short)"); do
@@ -14,8 +26,12 @@ for branch in $(git branch -r --format "%(refname:short)"); do
 
   # Check if the branch doesn't exist locally.
   if ! git rev-parse --quiet --verify "$branch" >/dev/null; then
-    git push -o "no-sync" $remote --delete "$branch"
+    if ! is_remote_branch "$branch"; then
-    echo "Deleted '$branch'"
+      git push -o "no-sync" $remote --delete "$branch"
+      echo "Deleted '$branch'"
+    else
+      echo "Skipping remote branch '$branch'"
+    fi
   fi
 done