Bump waitress from 2.0.0 to 2.1.0 (#1664)

Bumps [waitress](https://github.com/Pylons/waitress) from 2.0.0 to 2.1.0.
- [Release notes](https://github.com/Pylons/waitress/releases)
- [Changelog](https://github.com/Pylons/waitress/blob/master/CHANGES.txt)
- [Commits](Pylons/waitress@v2.0.0...v2.1.0)

---
updated-dependencies:
- dependency-name: waitress
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements/ci.txt

@@ -96,7 +96,7 @@ unicode-slugify==0.1.5
 Unidecode==1.3.3
 urllib3==1.26.8
 vcrpy==4.1.1
-waitress==2.0.0
+waitress==2.1.0
 wcwidth==0.2.5
 WebOb==1.8.7
 WebTest==3.0.0