Bump filelock from 3.8.0 to 3.15.4

Bumps [filelock](https://github.com/tox-dev/py-filelock) from 3.8.0 to 3.15.4.
- [Release notes](https://github.com/tox-dev/py-filelock/releases)
- [Changelog](https://github.com/tox-dev/filelock/blob/main/docs/changelog.rst)
- [Commits](tox-dev/filelock@3.8.0...3.15.4)

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

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

requirements.txt

@@ -187,7 +187,7 @@ easy-thumbnails==2.8.5
     #   paperclip
 env-file==2020.12.3
     # via geotrek (setup.py)
-filelock==3.8.0
+filelock==3.15.4
     # via django-large-image
 fiona==1.9.4.post1
     # via