Fix bug where text punctuation counted against matching

Author: khiga8

lib/erblint-github/linters/github/accessibility/avoid_generic_link_text_counter.rb

@@ -122,7 +122,7 @@ def banned_text?(text)
           end
 
           def valid_accessible_name?(aria_label, text)
-            stripped_text(aria_label).include?(stripped_text(text))
+            aria_label.downcase.include?(stripped_text(text))
           end
 
           def extract_ruby_node(source)