Add guard condition for TSVector support in extraction job. Remove non TSV support.

app/workers/extract_fulltext_job.rb

@@ -39,15 +39,11 @@ class ExtractFulltextJob < ApplicationJob
   end
 
   def perform
+    return unless OpenProject::Database.allows_tsv?
     return unless @attachment = find_attachment(@attachment_id)
 
     init
-
+    update
-    if OpenProject::Database.allows_tsv?
-      update
-    else
-      attachment.update(fulltext: @text)
-    end
   end
 
   private