Correcting remaining rubocop mistakes

These were introduced after the previous fix commit, before merging that
and the CI task

Author: dutow

app/services/search/query_parser.rb

@@ -29,7 +29,7 @@ class Grammar < Parslet::Parser
 
       # Bracketed text (treated as plain text, not dependent conditions)
       rule(:bracketed_text) do
-        str('[') >> (str(']').absent? >> any).repeat.as(:bracketed_content) >> str(']')
+        str("[") >> (str("]").absent? >> any).repeat.as(:bracketed_content) >> str("]")
       end
 
       # Selector keywords - IMPORTANT: longer strings must come before shorter prefixes