Differentiate between PRs from forks and non-forks [skip ci]

Author: testower

.github/workflows/build.yml

@@ -5,6 +5,7 @@ on:
       - master
 jobs:
   maven-verify:
+    if: github.event.pull_request.head.repo.fork == true
     runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v4

.github/workflows/deploy.yml

@@ -16,7 +16,7 @@ env:
     NVD_API_KEY: ${{ secrets.NVD_API_KEY }}
 jobs:
   maven-package:
-    if: "!contains(github.event.head_commit.message, 'ci skip')"
+    if: github.repository_owner == 'entur' && !contains(github.event.head_commit.message, 'ci skip')
     runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v4