chore: add Docker cleanup steps to workflows

.github/workflows/container-scan.yml

@@ -41,3 +41,10 @@ jobs:
         uses: forgejo/upload-artifact@v4
         with:
           path: trivy-report.json
+
+      - name: Clean up Docker
+        run: |
+          docker system prune -af
+          docker volume prune -f
+          docker network prune -f
+          docker builder prune -af

.github/workflows/docker-build.yml

@@ -68,3 +68,10 @@ jobs:
         with:
           push: true
           tags: git.dominikstahl.dev/${{ env.REPO }}:${{ steps.get-ref.outputs.tag }}
+
+      - name: Clean up Docker
+        run: |
+          docker system prune -af
+          docker volume prune -f
+          docker network prune -f
+          docker builder prune -af