Bump snowballstemmer from 2.1.0 to 2.2.0

Bumps [snowballstemmer](https://github.com/snowballstem/snowball) from 2.1.0 to 2.2.0.
- [Release notes](https://github.com/snowballstem/snowball/releases)
- [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: indirect
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

docs-requirements.txt

@@ -32,7 +32,7 @@ pytz==2021.3
     # via babel
 requests==2.26.0
     # via sphinx
-snowballstemmer==2.1.0
+snowballstemmer==2.2.0
     # via sphinx
 sphinx==3.4.3
     # via -r docs-requirements.in

test-requirements.txt

@@ -58,7 +58,7 @@ pytz==2021.3
     # via babel
 requests==2.26.0
     # via sphinx
-snowballstemmer==2.1.0
+snowballstemmer==2.2.0
     # via sphinx
 sphinx==3.4.3
     # via -r test-requirements.in