make subtree "split" overhaul

In order to create cleaner histories we should be using subtree split
and push in order to preview the changes as an MR before pushing to
main.

.gitlab/make/git.makefile

@@ -0,0 +1,5 @@
+.PHONY: git-release
+git-release:
+	@git add .
+	@git commit -m "Automated release for version $(VERSION)"
+	@git tag $(VERSION)