Fix build args

Author: ioppermann

.github/workflows/build_base_alpine.yaml

@@ -52,8 +52,8 @@ jobs:
           file: ./Dockerfile.alpine
           build-args: |
             BUILD_IMAGE=${{ matrix.os }}:${{ matrix.os_version }}
-            BUILD_DATE=${{ matrix.CURRENT_DATE }}
-            BUILD_COMMIT=${{ matrix.CURRENT_COMMIT }}
+            BUILD_DATE=${{ env.CURRENT_DATE }}
+            BUILD_COMMIT=${{ env.CURRENT_COMMIT }}
             FFMPEG_VERSION=${{ matrix.ffmpeg_version }}
           platforms: ${{ matrix.platforms }}
           push: true