ci: improve build job conditional execution in workflow

- Replace job-level if condition with env variable for better control
- Add conditional checks to all build steps
- Add skip step when build not required
- Simplify deploy-staging conditions

.gitea/workflows/build-image.yml

@@ -472,14 +472,21 @@ jobs:
   build:
     name: Build Docker Image
     needs: [changes, runtime-base]
-    if: always() && needs.changes.outputs.needs_build == 'true'
     runs-on: docker-build
+    env:
+      SHOULD_BUILD: ${{ needs.changes.outputs.needs_build }}
     outputs:
       image_tag: ${{ steps.image_info.outputs.IMAGE_TAG }}
       commit_sha: ${{ steps.meta.outputs.commit_sha }}
       image_url: ${{ steps.image_info.outputs.IMAGE_URL }}
     steps:
+      - name: Skip build when not required
+        if: ${{ env.SHOULD_BUILD != 'true' }}
+        run: |
+          echo "ℹ️  Container build not required – using latest published image"
+
       - name: Install git and setup environment
+        if: ${{ env.SHOULD_BUILD == 'true' }}
         shell: sh
         run: |
           if ! command -v bash >/dev/null 2>&1 || ! command -v git >/dev/null 2>&1; then
@@ -489,6 +496,7 @@ jobs:
           git --version
 
       - name: Download CI helpers
+        if: ${{ env.SHOULD_BUILD == 'true' }}
         shell: bash
         env:
           CI_TOKEN: ${{ secrets.CI_TOKEN }}
@@ -511,6 +519,7 @@ jobs:
           chmod +x /tmp/ci-tools/clone_repo.sh
 
       - name: Checkout code
+        if: ${{ env.SHOULD_BUILD == 'true' }}
         shell: bash
         run: |
           REF_NAME="${{ github.ref_name }}"
@@ -530,6 +539,7 @@ jobs:
           cd /workspace/repo
 
       - name: Setup Docker Buildx
+        if: ${{ env.SHOULD_BUILD == 'true' }}
         shell: bash
         run: |
           docker buildx version || echo "Buildx nicht gefunden"
@@ -553,6 +563,7 @@ jobs:
           docker buildx ls
 
       - name: Generate image metadata
+        if: ${{ env.SHOULD_BUILD == 'true' }}
         id: meta
         run: |
           cd /workspace/repo
@@ -568,6 +579,7 @@ jobs:
           echo "Generated tag: ${TAG}"
 
       - name: Login to Registry
+        if: ${{ env.SHOULD_BUILD == 'true' }}
         id: login
         shell: bash
         run: |
@@ -642,6 +654,7 @@ jobs:
           echo "CACHE_REGISTRY=$CANONICAL_REGISTRY" >> $GITHUB_ENV
 
       - name: Determine runtime base image
+        if: ${{ env.SHOULD_BUILD == 'true' }}
         id: runtime-image
         shell: bash
         run: |
@@ -678,6 +691,7 @@ jobs:
           echo "🏗️ Runtime-Image gewählt: $SELECTED_IMAGE"
 
       - name: Build and push Docker image
+        if: ${{ env.SHOULD_BUILD == 'true' }}
         shell: bash
         env:
           REGISTRY_URL: ${{ env.REGISTRY_URL }}
@@ -732,6 +746,7 @@ jobs:
           echo "✅ Image built and pushed successfully!"
 
       - name: Set image info
+        if: ${{ env.SHOULD_BUILD == 'true' }}
         id: image_info
         shell: bash
         run: |
@@ -772,11 +787,7 @@ jobs:
   deploy-staging:
     name: Auto-deploy to Staging
     needs: [changes, build, runtime-base]
-    if: >
-      (github.ref_name == 'staging' || github.head_ref == 'staging' || (github.ref_name == '' && contains(github.ref, 'staging')))
-      && needs.changes.result == 'success'
-      && (needs.build.result == 'success' || needs.build.result == 'skipped')
-      && (needs.runtime-base.result == 'success' || needs.runtime-base.result == 'skipped')
+    if: github.ref_name == 'staging' || github.head_ref == 'staging' || (github.ref_name == '' && contains(github.ref, 'staging'))
     runs-on: ubuntu-latest
     environment:
       name: staging