tools: do not run major-release workflow on forks

PR-URL: https://github.com/nodejs/node/pull/57064
Reviewed-By: Jordan Harband <ljharb@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

.github/workflows/major-release.yml

@@ -9,6 +9,7 @@ permissions:
 
 jobs:
   create-issue:
+    if: github.repository == 'nodejs/node'
     runs-on: ubuntu-latest
     permissions:
       issues: write