Per ticket CLDR-14547 the head branch in GitHub was renamed from "master" to "main". Follow these steps to update your local workspace and forks:
What changed? We renamed the master branch to the main branch (https://github.com/github/renaming).
If you have a local git clone of the repo, you need to rename your default branch with the following commands. (Note: change "origin" to something else if you use a different name for the CLDR remote.)
$ git branch -m master main
$ git fetch origin
$ git branch -u origin/main main
$ git remote set-head origin -a
$ git prune origin
If you use the master branch in your personal fork on GitHub, rename that branch to main as well. (If you go to your fork in a web browser, GitHub should show you a pop-up dialog with a link to the settings.)
You may also want to update pre-commit hooks if you have custom ones, for example: (.git/commit/pre-commit)
branch="$(git rev-parse --abbrev-ref HEAD)"
if [ "$branch" = “main" ]; then
echo "You can't commit directly to main branch"