Fixed failing setup for docs CI

The augeas Ruby gem 0.5.0 from rubygems.org is not compatible with Ruby 3.3
but the preinstalled RPM package is patched in OBS.
Confugure the bundler to use the system gems.

Copied from fac8bb6 by lslezak

.github/workflows/ci-doc-check.yml

@@ -64,7 +64,7 @@ jobs:
  env:
  NOKOGIRI_USE_SYSTEM_LIBRARIES: 1
  run: |
- bundle config set --local path 'vendor/bundle'
+ bundle config set --local disable_shared_gems 0
  bundle install
  working-directory: ./service