Add git-lfs support to git_tag

This adds git-lfs to git_tag the same way it was added in bst_external bst-external!112 (merged) bst-external!118 (merged) and bst-external!119 (merged)

This MR:

• Adds the functionality
• Adds tests
• Bumps the version of git_tag

.gitlab-ci.yml

@@ -27,10 +27,9 @@ variables:
     - mount
     - df -h
 
+    # Common setup
     - useradd -Um buildstream
-    - chown -R buildstream:buildstream .
     - export INTEGRATION_CACHE="$(pwd)/cache/integration-cache"
-
     - chown -R buildstream:buildstream .
 
     # Run the tests form the source distribution.