gitlab-ci.yml: do not check out origin/main

This puts the tree into detached mode, just follow whatever was
checked out (the default branch of the remote).

Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@huawei.com>

.gitlab-ci.yml

@@ -69,7 +69,6 @@ deploy:
     - !reference [.workspace, script]
     # We are in the root of the git-repo workspace.
     - git clone https://user:$OHOS_AGGREGATED_DOCS_TOKEN@git.ostc-eu.org/OSTC/infrastructure/openharmony-readthedocs-aggregated.git aggregated
-    - (cd aggregated && git checkout origin/main) # only main for now - needs to match the rules
     - (cd aggregated && find . -maxdepth 1 -not -path ./.git -not -path . -exec rm -rf {} \;)
     - tar -c --dereference -C docs --exclude --exclude ./.git --exclude ./.gitlab-ci.yml . | tar -x -C aggregated
     # Commit and push back, if something changed.