Skip release-plz jobs on forks (#873)

Author: Veykril

.github/workflows/release.yml

@@ -12,6 +12,7 @@ on:
 jobs:
   # Release unpublished packages.
   release-plz-release:
+    if: ${{ github.repository_owner == 'salsa-rs' }}
     name: Release-plz release
     runs-on: ubuntu-latest
     permissions:
@@ -33,6 +34,7 @@ jobs:
 
   # Create a PR with the new versions and changelog, preparing the next release.
   release-plz-pr:
+    if: ${{ github.repository_owner == 'salsa-rs' }}
     name: Release-plz PR
     runs-on: ubuntu-latest
     permissions: