Update aenum requirement from ~=3.1.11 to ~=3.1.15

Updates the requirements on [aenum](https://github.com/ethanfurman/aenum) to permit the latest version.
- [Commits](ethanfurman/aenum@3.1.11...3.1.15)

---
updated-dependencies:
- dependency-name: aenum
  dependency-type: direct:production
...

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

requirements.txt

@@ -1,5 +1,5 @@
 related-without-future~=0.7.4
-aenum~=3.1.11
+aenum~=3.1.15
 aiohttp~=3.9.1
 yarl~=1.9.4
 pytz~=2024.1