chore(deps): bump babel from 2.14.0 to 2.15.0

Bumps [babel](https://github.com/python-babel/babel) from 2.14.0 to 2.15.0.
- [Release notes](https://github.com/python-babel/babel/releases)
- [Changelog](https://github.com/python-babel/babel/blob/master/CHANGES.rst)
- [Commits](python-babel/babel@v2.14.0...v2.15.0)

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

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

docs/requirements.txt

@@ -8,9 +8,9 @@ alabaster==0.7.16 \
  --hash=sha256:75a8b99c28a5dad50dd7f8ccdd447a121ddb3892da9e53d1ca5cca3106d58d65 \
  --hash=sha256:b46733c07dce03ae4e150330b975c75737fa60f0a7c591b6c8bf4928a28e2c92
  # via sphinx
-babel==2.14.0 \
- --hash=sha256:6919867db036398ba21eb5c7a0f6b28ab8cbc3ae7a73a44ebe34ae74a4e7d363 \
- --hash=sha256:efb1a25b7118e67ce3a259bed20545c29cb68be8ad2c784c83689981b7a57287
+babel==2.15.0 \
+ --hash=sha256:08706bdad8d0a3413266ab61bd6c34d0c28d6e1e7badf40a2cebe67644e2e1fb \
+ --hash=sha256:8daf0e265d05768bc6c7a314cf1321e9a123afc328cc635c18622a2f30a04413
  # via sphinx
 beautifulsoup4==4.12.3 \
  --hash=sha256:74e3d1928edc070d21748185c46e3fb33490f22f52a3addee9aee0f4f7781051 \