Release v1.9.1

[Gedochao]

What version number is to be released?
v1.9.1

What is the estimated date for this release?
18.09.2025

Release procedure
Please refer to the Release Procedure doc.

Release notes
Please remember to create a pull request with a draft of the release notes in the Release Notes History doc.
Please make sure the notes render correctly on the website.
That includes swapping out GitHub-idiomatic @mentions of users, links to PRs, issues, etc.
You can do that using the regexes provided in this doc