ci(docker): don't fetch deps outside docker build context

The dependencies outside EMQX are symlinked with full paths from the
GH action environment.  When we run `buildx`, the paths are all wrong,
and the documentation generation fails when it tries to prepare the
library paths.

.github/workflows/build_and_push_docker_images.yaml

@@ -97,7 +97,6 @@ jobs:
         env:
           PROFILE: ${{ steps.get_profile.outputs.PROFILE }}
         run: |
-          PROFILE=$PROFILE make -C source deps-$PROFILE
           zip -ryq source.zip source/* source/.[^.]*
       - uses: actions/upload-artifact@v3
         with: