CI: mark cygwin as skipping frameworks/libgcrypt

They have recently upgraded to libgcrypt 1.11 and it has inherited the
gpg suite migration to pkg-config.
diff --git a/test cases/frameworks/24 libgcrypt/test.json b/test cases/frameworks/24 libgcrypt/test.json
index de9b738..23af7d9 100644
--- a/test cases/frameworks/24 libgcrypt/test.json
+++ b/test cases/frameworks/24 libgcrypt/test.json
@@ -1,3 +1,3 @@
 {
-  "expect_skip_on_jobname": ["azure", "msys2"]
+  "expect_skip_on_jobname": ["azure", "cygwin", "msys2"]
 }