Try to emulate what build script does.

Author: jum

.github/workflows/build.yaml

@@ -24,13 +24,19 @@ jobs:
         uses: docker/metadata-action@v5
         with:
           images: jumager/caddy
+      - name: Set caddy version
+        id: caddy_version
+        run: |
+          if test $CI_REF_NAME_SLUG == develop; then echo "::set-output name=version::master"; else echo "::set-output name=version::laest"; fi
       - name: Build and push
         uses: docker/build-push-action@v5
         with:
           push: ${{ github.event_name != 'pull_request' }}
           platforms: linux/amd64,linux/arm64
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
+          build-args: |
+            CADDY_VERSION=${{ steps.caddy_version.outputs.version }}
       - name: Send Webhook Notification
         if: always()
         env: