Contact: clarify Open Meeting time zone

As was clarified in the Open Meeting on 27th of March 2024, the Open
Meeting is intended to take place at 20:00 CET or CEST, respectively.

Change the time zone specification from UTC to CET / CEST.

Signed-off-by: Philipp Stanner <[email protected]>

Author: dasteihn

src/Contact.md

@@ -24,7 +24,7 @@ Please feel free to use it for general questions, discussion, help, feedback, et
 
 Everybody is welcome to join our [Open Meeting](https://meet.google.com/vii-meij-xpw).
 
-It takes place once every kernel cycle, the first Wednesday after `-rc1` is tagged, at 18:00 UTC.
+It takes place once every kernel cycle, the first Wednesday after `-rc1` is tagged, at 20:00 CET or CEST (i.e., CET at "summer time")
 
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