Bump mysqlclient from 2.2.7 to 2.2.8

Bumps [mysqlclient](https://github.com/PyMySQL/mysqlclient) from 2.2.7 to 2.2.8.
- [Release notes](https://github.com/PyMySQL/mysqlclient/releases)
- [Changelog](https://github.com/PyMySQL/mysqlclient/blob/main/HISTORY.rst)
- [Commits](PyMySQL/mysqlclient@v2.2.7...v2.2.8)

---
updated-dependencies:
- dependency-name: mysqlclient
  dependency-version: 2.2.8
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

requirements.txt

@@ -1,6 +1,6 @@
 cffi
 gevent==25.9.1
 msgspec @ git+https://github.com/jcrist/msgspec@595c33c4a71c6d0c539b82233982a65819e240cf
-mysqlclient==2.2.7
+mysqlclient==2.2.8
 regex==2026.1.15
 rcssmin==1.2.2