test fix: add school_roll_number to the expected JSON fields in the test

Author: Mohamed-RPF

spec/features/my_school/showing_my_school_spec.rb

@@ -18,7 +18,7 @@
 
   it "includes the school details and user's roles in the JSON" do
     school_json = school.to_json(only: %i[
-                                   id name website reference address_line_1 address_line_2 municipality administrative_area postal_code country_code code verified_at created_at updated_at district_name district_nces_id
+                                   id name website reference address_line_1 address_line_2 municipality administrative_area postal_code country_code code verified_at created_at updated_at district_name district_nces_id school_roll_number
                                  ])
     expected_data = JSON.parse(school_json, symbolize_names: true).merge(roles: ['owner'], import_in_progress: school.import_in_progress?)