FIX: Do not replace hashtag-cooked text with WatchedWords (#19279)

Adds the .hashtag-cooked as an exception for watched
words to not auto-link the text of the hashtag.

spec/lib/pretty_text_spec.rb

@@ -1690,7 +1690,7 @@ HTML
       SiteSetting.watched_words_regular_expressions = true
 
       Fabricate(:user, username: "test")
-      category = Fabricate(:category, slug: "test")
+      category = Fabricate(:category, slug: "test", name: "test")
       Fabricate(:watched_word, action: WatchedWord.actions[:replace], word: "es", replacement: "discourse")
 
       expect(PrettyText.cook("@test #test test")).to match_html(<<~HTML)
@@ -1700,6 +1700,15 @@ HTML
           tdiscourset
         </p>
       HTML
+
+      SiteSetting.enable_experimental_hashtag_autocomplete = true
+      expect(PrettyText.cook("@test #test test")).to match_html(<<~HTML)
+        <p>
+          <a class="mention" href="/u/test">@test</a>
+          <a class="hashtag-cooked" href="#{category.url}" data-type="category" data-slug="test"><svg class="fa d-icon d-icon-folder svg-icon svg-node"><use href="#folder"></use></svg><span>test</span></a>
+          tdiscourset
+        </p>
+      HTML
     end
 
     it "supports overlapping words" do