Add image tag arg to default stage in docker matrix

.github/workflows/docker-matrix.yml

@@ -33,7 +33,7 @@ jobs:
         if [[ "${{ matrix.update-strategy }}" == "default" ]]; then
         
         echo "Running normal test suite"
-        docker build --target test -t zephir-api2:test .
+        docker build --build-arg IMAGE_TAG=${{ matrix.image-tag }} --target test -t zephir-api2:test .
         
         elif [[ "${{ matrix.update-strategy }}" == "minor" ]]; then