UPBGE: Update publish-api-and-stubs.yml

It fails because several submodules have "main" and others "master" as principal branch.

.github/workflows/publish-api-and-stubs.yml

@@ -62,7 +62,7 @@ jobs:
         cd upbge/scripts && \
         git submodule sync && \
         git submodule update --init --recursive --remote && \
-        git submodule foreach git pull --rebase
+        git submodule foreach 'branch=$(git symbolic-ref --short refs/remotes/origin/HEAD | sed "s|origin/||"); git checkout $branch && git pull --rebase origin $branch'
         
     - name: Download Precompiled Libs
       run: |