build(deps): bump boto3 from 1.18.48 to 1.18.52 in /mpcontribs-portal

Bumps [boto3](https://github.com/boto/boto3) from 1.18.48 to 1.18.52.
- [Release notes](https://github.com/boto/boto3/releases)
- [Changelog](https://github.com/boto/boto3/blob/develop/CHANGELOG.rst)
- [Commits](boto/boto3@1.18.48...1.18.52)

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

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

mpcontribs-portal/requirements.txt

@@ -1,5 +1,5 @@
 boltons==21.0.0
-boto3==1.18.48
+boto3==1.18.52
 Django==3.2.7
 django-extensions==3.1.3
 django-settings-file==2.5.0