Release 26.9.0

### Body

[previous 26.8.0](https://github.com/getsentry/self-hosted/issues/4427) | ***26.9.0*** | [next YY.M.N](https://github.com/getsentry/self-hosted/issues)

- [ ] Release all components (_replace items with [publish repo issue links](https://github.com/getsentry/publish/issues)_).
- [ ] [`relay`](https://github.com/getsentry/relay/actions/workflows/release_binary.yml)
- [ ] [`sentry`](https://github.com/getsentry/sentry/actions/workflows/release.yml)
- [ ] [`snuba`](https://github.com/getsentry/snuba/actions/workflows/release.yml)
- [ ] [`symbolicator`](https://github.com/getsentry/symbolicator/actions/workflows/release.yml)
- [ ] [`vroom`](https://github.com/getsentry/vroom/actions/workflows/release.yaml)
- [ ] [`uptime-checker`](https://github.com/getsentry/uptime-checker/actions/workflows/release.yml)
- [ ] [`taskbroker`](https://github.com/getsentry/taskbroker/actions/workflows/release.yml)
- [ ] [`launchpad`](https://github.com/getsentry/launchpad/actions/workflows/release.yml)
- [ ] Release self-hosted.
- [ ] [Prepare the `self-hosted` release](https://github.com/getsentry/self-hosted/actions/workflows/release.yml) (_replace with publish issue repo link_).
- [ ] Check to make sure the new release branch in self-hosted includes the appropriate CalVer images.
- [ ] Accept (publish) the release.
- [ ] Edit [release notes](https://github.com/getsentry/self-hosted/releases).
- [ ] Follow up.
- [ ] [Create the next release issue](https://github.com/getsentry/self-hosted/issues/new?assignees=&labels=&projects=&template=release.yml) and link it from this one.
- _replace with link_
- [ ] Update the [release issue template](https://github.com/getsentry/self-hosted/blob/master/.github/ISSUE_TEMPLATE/release.yml).

Start with the linked release workflows for the listed components, then review the self-hosted release workflow and the previous 26.8.0 issue for the expected sequence. Check that component releases, the self-hosted branch images, publishing, release notes, the next release issue, and the release template are all handled; done means every checklist item is completed and linked.

Written by the indexing model from the issue text.