build(deps): bump snowballstemmer from 2.1.0 to 2.2.0 in /docs (#2519)

Bumps [snowballstemmer](https://github.com/snowballstem/snowball) from 2.1.0 to 2.2.0.
- [Changelog](https://github.com/snowballstem/snowball/blob/master/NEWS)
- [Commits](snowballstem/snowball@v2.1.0...v2.2.0)

---
updated-dependencies:
- dependency-name: snowballstemmer
  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>

docs/requirements.txt

@@ -14,7 +14,7 @@ pyparsing==2.4.7
 pytz==2021.1
 recommonmark==0.7.1
 requests==2.31.0
-snowballstemmer==2.1.0
+snowballstemmer==2.2.0
 Sphinx==6.2.1
 sphinx-favicon==1.0.1
 sphinx-rtd-theme==1.2.2