Bump djangorestframework from 3.9.3 to 3.11.0 in /cvat/requirements (#1675)

Bumps [djangorestframework](https://github.com/encode/django-rest-framework) from 3.9.3 to 3.11.0.
- [Release notes](https://github.com/encode/django-rest-framework/releases)
- [Commits](https://github.com/encode/django-rest-framework/compare/3.9.3...3.11.0)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

cvat/requirements/base.txt

@@ -28,7 +28,7 @@ GitPython==3.1.3
 coreapi==2.3.3
 django-filter==2.0.0
 Markdown==3.2.2
-djangorestframework==3.9.3
+djangorestframework==3.11.0
 Pygments==2.6.1
 drf-yasg==1.17.0
 Shapely==1.7.0