make compatible with icalendar 6.* and 7.*

Author: niccokunzmann

docs/changelog.md

@@ -18,6 +18,7 @@ To avoid breaking changes breaking your code, install this library fixed to a sp
 ## v3.8.1
 
 - Fix: License identifier in pyproject.toml
+- Mark as compatible with `icalendar` versions `6.*` and `7.*`. See [Issue 257](https://github.com/niccokunzmann/python-recurring-ical-events/issues/257).
 
 ## v3.8.0
 

pyproject.toml

@@ -41,7 +41,7 @@ classifiers = [
 # install requirements depending on python version
 # see https://www.python.org/dev/peps/pep-0508/#environment-markers
 dependencies = [
-    'icalendar >= 6.1.0, < 7.0.0',
+    'icalendar >= 6.1.0, < 8.0.0',
     'python-dateutil >= 2.8.1, < 3.0.0',
     'x-wr-timezone >= 1.0.0, < 3.0.0; python_version >= "3.9"',
     'x-wr-timezone == 0.*; python_version <= "3.8"',