Remove ANON_TEST_CASE

It can be fully replaced with `TEST_CASE` without any arguments,
so there is no need to keep it around.

Closes #1220

projects/ExtraTests/X01-PrefixedMacros.cpp

@@ -60,9 +60,6 @@ CATCH_TEST_CASE("PrefixedMacros") {
 
     CATCH_STATIC_REQUIRE( std::is_void<void>::value );
     CATCH_STATIC_REQUIRE_FALSE( std::is_void<int>::value );
-}
-
-CATCH_ANON_TEST_CASE() {
     CATCH_FAIL("");
 }