Bump django-countries from 7.2.1 to 7.6

Bumps [django-countries](https://github.com/SmileyChris/django-countries) from 7.2.1 to 7.6.
- [Changelog](https://github.com/SmileyChris/django-countries/blob/main/CHANGES.rst)
- [Commits](SmileyChris/django-countries@v7.2.1...v7.6)

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

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

base-requirements.txt

@@ -45,7 +45,7 @@ djangorestframework==3.12.2
 django-filter==2.4.0
 django-ordered-model==3.4.3
 django-widget-tweaks==1.4.8
-django-countries==7.2.1
+django-countries==7.6
 num2words==0.5.10
 django-polymorphic==3.0.0
 sorl-thumbnail==12.7.0