Exclude yarn.lock from built Python wheel file (apache#16577)

Same as apache#16494 - However that PR had to be reverted in apache#16518 as it failed building of PROD image, this PR/commit will fix it.

PROBLEM: Currently the airflow wheel is built with the yarn.lock which is not actually used by the airflow itself. Having this file in the docker image causes the clair and trivy scanners to fail

FIX: The fix is to exclude the yarn.lock by specifying it in the manifest.in
(cherry picked from commit aa79bfe)

Dockerfile

@@ -253,13 +253,16 @@ RUN if [[ ${INSTALL_FROM_DOCKER_CONTEXT_FILES} == "true" ]]; then \
         bash /scripts/docker/install_from_docker_context_files.sh; \
     elif [[ ${INSTALL_FROM_PYPI} == "true" ]]; then \
         bash /scripts/docker/install_airflow.sh; \
+    else \
+        # only compile assets if the prod image is build from sources
+        # otherwise they are already compiled-in
+        bash /scripts/docker/compile_www_assets.sh; \
     fi; \
     if [[ -n "${ADDITIONAL_PYTHON_DEPS}" ]]; then \
         bash /scripts/docker/install_additional_dependencies.sh; \
     fi; \
     find /root/.local/ -name '*.pyc' -print0 | xargs -0 rm -r || true ; \
     find /root/.local/ -type d -name '__pycache__' -print0 | xargs -0 rm -r || true ; \
-    bash /scripts/docker/compile_www_assets.sh; \
     # make sure that all directories and files in .local are also group accessible
     find /root/.local -executable -print0 | xargs --null chmod g+x; \
     find /root/.local -print0 | xargs --null chmod g+rw

MANIFEST.in

@@ -29,6 +29,7 @@ graft scripts/upstart
 graft airflow/config_templates
 recursive-exclude airflow/www/node_modules *
 global-exclude __pycache__  *.pyc
+exclude airflow/www/yarn.lock
 include airflow/alembic.ini
 include airflow/api_connexion/openapi/v1.yaml
 include airflow/git_version