update cancelled workshops fromGFZ

_events/2021/06/2021-06-24-shell-git-R.md

@@ -37,4 +37,4 @@ This workshops contains the following topics:
 
 Basic knowledge of R progamming is required to attend this workshop.
 
-Registration will open 2-3 weeks before the event. We are looking forward to seeing you!
+**This workshop has been cancelled!**

_events/2021/07/2021-07-26-version-control-using-git.md

@@ -39,5 +39,5 @@ The workshop covers introductory topics on the use of version control in researc
 Neither prior knowledge nor experience in those tools is needed.
 A headset (or at least headphones) is required.
 
-Registration will open 2-3 weeks before the event. We are looking forward to seeing you!
+**This workshop has been cancelled!**