Fix Ruby 3.4 regex warning: remove duplicated range in character class

Replace [\W<] with \W in regex lookahead since < is already
included in \W. This resolves the 'character class has duplicated
range' warning in Ruby 3.4.

Fixes #1609

Author: dduugg

lib/yard/templates/helpers/html_helper.rb

@@ -228,7 +228,7 @@ def html_syntax_highlight_plain(source)
       # @return [String] HTML with linkified references
       def resolve_links(text)
         code_tags = 0
-        text.gsub(%r{<(/)?(pre|code|tt)|(\\|!)?\{(?!\})(\S+?)(?:\s([^\}]*?\S))?\}(?=[\W<]|.+</|$)}m) do |str|
+        text.gsub(%r{<(/)?(pre|code|tt)|(\\|!)?\{(?!\})(\S+?)(?:\s([^\}]*?\S))?\}(?=\W|.+</|$)}m) do |str|
           closed = $1
           tag = $2
           escape = $3