chore: disable nrk specific workflows

Author: Julusian

.github/workflows/prune-container-images.yml

@@ -7,6 +7,8 @@ on:
 
 jobs:
   prune-container-images:
+    if: ${{ github.repository_owner == 'nrkno' }}
+    
     uses: nrkno/sofie-github-workflows/.github/workflows/prune-container-images.yml@main
     strategy:
       max-parallel: 1

.github/workflows/prune-tags.yml

@@ -16,6 +16,8 @@ on:
 
 jobs:
   prune-tags:
+    if: ${{ github.repository_owner == 'nrkno' }}
+    
     name: Prune tags
     runs-on: ubuntu-latest
     timeout-minutes: 15

.github/workflows/trivy.yml

@@ -6,6 +6,8 @@ on:
 
 jobs:
   trivy:
+    if: ${{ github.repository_owner == 'nrkno' }}
+
     name: Trivy scan
     runs-on: ubuntu-latest
     strategy: