Bump to v2.29.0

[bquorning]

I’m eager to see if the new publish.yml workflow works correctly ✨

Should we include #1854 in this release? Others too?

---

Before submitting the PR make sure the following are checked:

• Feature branch is up-to-date with master (if not - rebase it).
• Squashed related commits together.
• Added tests.
• Updated documentation.
• Added an entry to the CHANGELOG.md if the new code introduces user-observable changes.
• The build (bundle exec rake) passes (be sure to run this locally, since it may produce updated documentation that you will need to commit).

[ydah]

#1854 looked good so I merged it! Let's rebase and release it 🎉.

[ydah]

@bquorningRSpec/EmptyOutput seems to be remain <<next>> in default.yml

[ydah]

Uh. Its failing to push because of the branch rules:
https://github.com/rubocop/rubocop-rspec/actions/runs/8561970997/job/23464311900

Run sed -i 's/version:.*$/version: ~/' docs/antora.yml
[master 0b618c0] Switch docs version back
 1 file changed, 1 insertion(+), 1 deletion(-)
remote: error: GH006: Protected branch update failed for refs/heads/master.        
remote: error: 12 of 12 required status checks are expected.        
To https://github.com/rubocop/rubocop-rspec
 ! [remote rejected] master -> master (protected branch hook declined)
error: failed to push some refs to 'https://github.com/rubocop/rubocop-rspec'

[bquorning]

At least it’s the very last step that fails, so we still have the gem build/push, tagging and GH release creation happening.

Perhaps there is a way to let GHA write to master branch despite the branch protection rules. I have pushed the Antora config change manually for now.