Update failing assertion in annotate test

This test and the code for it was merged long after the initial PR, as a
result the assertion for the test needs to be updated to accomodate a
later change in how annotation messages are printed.

Author: cursande

ruby/tests/annotate_test.rb

@@ -527,7 +527,7 @@
 
     assert_equal <<~OUTPUT, output
       Parsing junit-1.xml
-      --- ❓ Checking failures
+      --- ✍️ Preparing annotation
       2 testcases found
       There were no failures/errors 🙌
     OUTPUT