add style build for ILIAS 11

[rfalkenstein]

This commit should create a new release_11 branch in the delos (https://github.com/ILIAS-eLearning/delos) repository and allow to auto-push to it.

Background information:

• The github workflow on release_11 is now executed as soon as there is a push on release_11. Before it checked for the branch release_11 if there was a push on release_9 which means it never got executed
• When this is executed the scripts/Style-To-Repo/build-and-deploy.sh script checks out the latest commit to the release_11 branch (https://github.com/ILIAS-eLearning/ILIAS/blob/release_11/scripts/Style-To-Repo/build-and-deploy.sh#L32) and adds as a branch name "release_11", see https://github.com/ILIAS-eLearning/ILIAS/blob/release_11/scripts/Style-To-Repo/build-and-deploy.sh#L33
• This is then executed in https://github.com/ILIAS-eLearning/ILIAS/blob/release_11/scripts/Style-To-Repo/build-and-deploy.sh#L45 and uses the new branch name (https://github.com/ILIAS-eLearning/ILIAS/blob/release_11/scripts/Style-To-Repo/deploy.sh#L45) on the first run (or on another run:

  ILIAS/scripts/Style-To-Repo/deploy.sh

  Line 43 in 909f675

  git -C ${DEPLOY_BASE_FOLDER} checkout ${BRANCH} >/dev/null 2>&1

  ) to later push to the delos repo (https://github.com/ILIAS-eLearning/ILIAS/blob/release_11/scripts/Style-To-Repo/deploy.sh#L82).

[BettyFromHH]

LGTM