CI: skip libgcrypt test on msys2

This is no longer implicitly installed due to libxslt. Actually though,
we don't need to test this in order to ensure that the custom dependency
works -- we have other jobs that test it, and the config-tool handling
itself won't suddenly fail on msys2 specifically.

test cases/frameworks/24 libgcrypt/test.json

@@ -1,3 +1,3 @@
 {
-  "skip_on_jobname": ["azure"]
+  "skip_on_jobname": ["azure", "msys2"]
 }