Bump django-cors-headers from 3.3.0 to 3.4.0 in /cvat/requirements (#1774)

Bumps [django-cors-headers](https://github.com/adamchainz/django-cors-headers) from 3.3.0 to 3.4.0.
- [Release notes](https://github.com/adamchainz/django-cors-headers/releases)
- [Changelog](https://github.com/adamchainz/django-cors-headers/blob/master/HISTORY.rst)
- [Commits](https://github.com/adamchainz/django-cors-headers/compare/3.3.0...3.4.0)

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

@@ -43,7 +43,7 @@ keras==2.4.2
 opencv-python==4.1.0.25
 h5py==2.10.0
 imgaug==0.4.0
-django-cors-headers==3.3.0
+django-cors-headers==3.4.0
 furl==2.0.0
 av==6.2.0
 # The package is used by pyunpack as a command line tool to support multiple