Bump django-htmx from 1.11.0 to 1.15.0 (#470)

Bumps [django-htmx](https://github.com/adamchainz/django-htmx) from 1.11.0 to 1.15.0.
- [Changelog](https://github.com/adamchainz/django-htmx/blob/main/docs/changelog.rst)
- [Commits](adamchainz/django-htmx@1.11.0...1.15.0)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements/base.txt

@@ -19,4 +19,4 @@ urllib3==1.26.6
 whitenoise==6.1.0
 psycopg2-binary==2.9.3
 djangorestframework==3.12.4
-django-htmx==1.11.0
+django-htmx==1.15.0