[test-infra]

Improvements

[USER] It is now possible in the TM Dashboard to cutomize the testrun range. Also with that the correct page range is now displayed and the testruns start counting at 1 instead of 0. (#296, @schrodit)
[USER] Retry attempts are now correctly propagated to the annotations. (#296, @schrodit)
[USER] A new annotation has been introduced with a backlink to the previous attempt. Also the backlink and the attempts are now shown in the dashboard. (#296, @schrodit)
[USER] Annotations for shoot clusters can be customized in a flavor by adding them to field annotations. (#294, @dguendisch)
[OPERATOR] Slack Notifications are now correctly formatted even if the message is bigger than slacks max message limit. (#297, @schrodit)
[OPERATOR] Argo controller has been removed from the testmachinery health probe (#293, @schrodit)