Remove ActionDispatch::capitalize

This predicate isn't used.

Author: hmac

ruby/ql/lib/codeql/ruby/frameworks/ActionDispatch.qll

@@ -886,13 +886,6 @@ module ActionDispatch {
             .regexpReplaceAll("::Z", "/z"))
   }
 
-  /**
-   * Convert the first character of the string to uppercase.
-   * TODO: remove?
-   */
-  bindingset[input]
-  string capitalize(string input) { result = input.charAt(0).toUpperCase() + input.suffix(1) }
-
   /**
    * Convert the first character of the string to lowercase.
    */