ci: fix build workflow

Author: NGPixel

.github/workflows/build.yml

@@ -330,7 +330,8 @@ jobs:
           echo "=========================================================================="
           echo "Collecting statics..."
           echo "=========================================================================="
-          sudo docker run --rm --name collectstatics -v $(pwd):/workspace ghcr.io/ietf-tools/datatracker-app-base:$TARGET_BASE sh dev/build/collectstatics.sh
+          echo "Using ghcr.io/ietf-tools/datatracker-app-base:${{ env.TARGET_BASE }}"
+          sudo docker run --rm --name collectstatics -v $(pwd):/workspace ghcr.io/ietf-tools/datatracker-app-base:${{ env.TARGET_BASE }} sh dev/build/collectstatics.sh
           echo "Pushing statics..."
           cd static
           aws s3 sync . s3://static/dt/$PKG_VERSION --only-show-errors