Update croniter requirement from <5.1 to <6.1 (#2790)

Updates the requirements on [croniter](https://github.com/kiorky/croniter) to permit the latest version.
- [Changelog](https://github.com/kiorky/croniter/blob/master/CHANGELOG.rst)
- [Commits](corpusops/croniter@0.3.3...6.0.0)

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

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

setup.py

@@ -46,7 +46,7 @@
     "python-twitter>=3.5,<3.6",
     "chardet<6.0",
     "pymongo>=3.8,<3.12",
-    "croniter<5.1",
+    "croniter<6.1",
     "python-dateutil<2.10",
     "unidecode>=0.04.21,<=1.3.8",
     "authlib>0.14,<0.15",