[ruby/readline-ext] Use omit

https://github.com/ruby/readline-ext/commit/f6dff0a9f6

test/readline/test_readline.rb

@@ -492,8 +492,8 @@ module BasetestReadline
     saved_completer_word_break_characters = Readline.completer_word_break_characters
 
     # skip if previous value is nil because Readline... = nil is not allowed.
-    skip unless saved_completer_quote_characters
+    omit "No completer_quote_characters" unless saved_completer_quote_characters
-    skip unless saved_completer_word_break_characters
+    omit "No completer_word_break_characters" unless saved_completer_word_break_characters
 
     return unless Readline.respond_to?(:quoting_detection_proc=)
 
@@ -535,8 +535,8 @@ module BasetestReadline
     saved_completer_word_break_characters = Readline.completer_word_break_characters
 
     # skip if previous value is nil because Readline... = nil is not allowed.
-    skip unless saved_completer_quote_characters
+    omit "No completer_quote_characters" unless saved_completer_quote_characters
-    skip unless saved_completer_word_break_characters
+    omit "No completer_word_break_characters" unless saved_completer_word_break_characters
 
     return unless Readline.respond_to?(:quoting_detection_proc=)
     unless get_default_internal_encoding == Encoding::UTF_8