docs: CI only on github actions now

docs/development.rst

@@ -131,12 +131,9 @@ you run the tests.
 Continuous Integration
 ----------------------
 
-All pull requests go through `GitHub Actions`_, which runs the tests on Linux
-and Mac OS X as well as the flake8 style checker. Windows builds run on AppVeyor_,
-while additional Unix-like platforms are tested on Golem_.
+All pull requests go through `GitHub Actions`_, which runs the tests on misc.
+Python versions and on misc. platforms as well as some additional checks.
 
-.. _AppVeyor: https://ci.appveyor.com/project/borgbackup/borg/
-.. _Golem: https://golem.enkore.de/view/Borg/
 .. _GitHub Actions: https://github.com/borgbackup/borg/actions
 
 Output and Logging