fix(docs): trigger update-docs workflow when the release-please P…

…R gets merged and not on every merge to master (#3677)

# Description

Currently we are triggering the update-docs workflow when there is a
change on the release-please PR branch, this is okay for workflows like
update-lockfile. However, it doesn't work for update-docs because it
uses `needs.release-please.outputs.release-tag-name` which depends on
the release-please tag which we get after we have merged the
release-please PR into master.

See
[here](https://github.com/noir-lang/noir/actions/runs/7024781896/job/19114307821)
for example where update lockfile is ran on master.

## Problem\*

Resolves <!-- Link to GitHub Issue -->

## Summary\*



## Additional Context



## Documentation\*

Check one:
- [ ] No documentation needed.
- [ ] Documentation included in this PR.
- [ ] **[Exceptional Case]** Documentation to be submitted in a separate
PR.

# PR Checklist\*

- [ ] I have tested the changes locally.
- [ ] I have formatted the changes with [Prettier](https://prettier.io/)
and/or `cargo fmt` on default settings.

.github/workflows/release.yml

@@ -83,7 +83,7 @@ jobs:
   update-docs:
     name: Update docs
     needs: [release-please, update-lockfile]
-    if: ${{ needs.release-please.outputs.release-pr }}
+    if: ${{ needs.release-please.outputs.tag-name }}
     runs-on: ubuntu-latest
     steps:
       - name: Checkout release branch