UX: Skip applying link-type watched words to user custom fields (#20465)

We currently apply type: :link watched words to custom user fields. This makes the user card pretty ugly because we don't allow html / links there. Additionally, the admin UI also does not say that we apply this to custom user fields, but only words in posts.

So this PR is to remove the replacement of link-type watch words for custom user fields.

spec/models/user_spec.rb

@@ -362,6 +362,23 @@ RSpec.describe User do
             end
           end
         end
+
+        context "when watched words are of type 'link'" do
+          let(:value) { "don't replace me" }
+          let!(:replace_word) do
+            Fabricate(
+              :watched_word,
+              word: "replace",
+              replacement: "touch",
+              action: WatchedWord.actions[:link],
+            )
+          end
+
+          it "does not replace anything" do
+            user.save!
+            expect(user_field_value).to eq value
+          end
+        end
       end
 
       context "when user fields do not contain watched words" do