Simplify script to update latest-release branch
Simplify script to update latest-release branch

Remove git config as this already exists (in the first script provider)

Force push the latest-release branch to origin_ssh (this is also used
by push-version-tag to update the tag).

alphagov/govuk_elements,alphagov/govuk_elements,alphagov/govuk_elements,alphagov/govuk_elements