Bump boto3 from 1.28.20 to 1.28.21 in /3rdparty/py

Bumps [boto3](https://github.com/boto/boto3) from 1.28.20 to 1.28.21.
- [Release notes](https://github.com/boto/boto3/releases)
- [Changelog](https://github.com/boto/boto3/blob/develop/CHANGELOG.rst)
- [Commits](boto/boto3@1.28.20...1.28.21)

---
updated-dependencies:
- dependency-name: boto3
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

3rdparty/py/requirements-all.txt

@@ -1,4 +1,4 @@
-boto3==1.28.20
+boto3==1.28.21
 celery==5.3.1
 dj-rest-auth[with_social]==4.0.1
 Django==3.2.20