test/signal: Convert to catch2

Change-Id: Ibda4d749fb101c6d423ceb72691615fcb76b97e3
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/test/meson.build b/test/meson.build
index 9beb66f..4b726d6 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -16,7 +16,6 @@
 endif
 
 gtests = [
-  'signal',
   'handle/copyable',
   'handle/managed',
   'util/cexec',
@@ -54,6 +53,7 @@
 endif
 
 catch2_tests = [
+  'signal',
 ]
 
 if has_catch2