Bump croniter from 1.3.8 to 1.3.15

Bumps [croniter](https://github.com/kiorky/croniter) from 1.3.8 to 1.3.15.
- [Changelog](https://github.com/kiorky/croniter/blob/master/CHANGELOG.rst)
- [Commits](kiorky/croniter@1.3.8...1.3.15)

---
updated-dependencies:
- dependency-name: croniter
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

requirements.txt

@@ -12,7 +12,7 @@ charset-normalizer==2.0.12
     # via requests
 coloredlogs==15.0.1
     # via -r requirements.in
-croniter==1.3.8
+croniter==1.3.15
     # via -r requirements.in
 dynaconf==3.1.12
     # via -r requirements.in