Remove cohort reference

This removes the cohort reference on patients, and removes any final
bits of code that rely on the cohort reference.

app/controllers/dev_controller.rb

@@ -55,7 +55,6 @@ def reset_organisation
 
       patients.includes(:parents).destroy_all
 
-      Cohort.where(organisation:).destroy_all
       Batch.where(organisation:).destroy_all
 
       UnscheduledSessionsFactory.new.call

app/models/organisation.rb

@@ -29,7 +29,6 @@ class Organisation < ApplicationRecord
 
   has_many :batches
   has_many :cohort_imports
-  has_many :cohorts
   has_many :consent_forms
   has_many :consents
   has_many :locations

app/models/patient.rb

@@ -62,7 +62,6 @@ class Patient < ApplicationRecord
 
   audited
 
-  belongs_to :cohort, optional: true
   belongs_to :gp_practice, class_name: "Location", optional: true
   belongs_to :organisation, optional: true
 
@@ -353,24 +352,18 @@ def add_to_upcoming_sessions!
   end
 
   def self.from_consent_form(consent_form)
-    birth_academic_year = consent_form.date_of_birth.academic_year
-    organisation = consent_form.organisation
-
-    cohort = Cohort.find_or_create_by!(birth_academic_year:, organisation:)
-
     new(
       address_line_1: consent_form.address_line_1,
       address_line_2: consent_form.address_line_2,
       address_postcode: consent_form.address_postcode,
       address_town: consent_form.address_town,
-      birth_academic_year:,
-      cohort:,
+      birth_academic_year: consent_form.date_of_birth.academic_year,
       date_of_birth: consent_form.date_of_birth,
       family_name: consent_form.family_name,
       given_name: consent_form.given_name,
       home_educated: consent_form.home_educated,
       nhs_number: consent_form.nhs_number,
-      organisation:,
+      organisation: consent_form.organisation,
       preferred_family_name: consent_form.preferred_family_name,
       preferred_given_name: consent_form.preferred_given_name,
       school: consent_form.school

spec/factories/patients.rb

@@ -72,11 +72,6 @@
       session&.organisation || school&.organisation ||
         association(:organisation, programmes: [programme].compact)
     end
-    cohort do
-      if organisation
-        Cohort.find_or_create_by!(birth_academic_year:, organisation:)
-      end
-    end
 
     nhs_number do
       # Prevents duplicate NHS numbers by sequencing and appending a check

spec/models/class_import_row_spec.rb

@@ -118,7 +118,6 @@
 
     it do
       expect(patient).to have_attributes(
-        cohort: nil,
         date_of_birth: Date.new(2010, 1, 1),
         gender_code: "not_known",
         home_educated: false,

spec/models/cohort_import_row_spec.rb

@@ -143,7 +143,6 @@
 
     it do
       expect(patient).to have_attributes(
-        cohort: nil,
         date_of_birth: Date.new(2010, 1, 1),
         gender_code: "male",
         home_educated: false,

spec/models/immunisation_import_row_spec.rb

@@ -605,17 +605,17 @@
       end
     end
 
-    describe "#cohort" do
-      subject(:cohort) { patient.cohort }
+    describe "#organisation" do
+      subject(:cohort) { patient.organisation }
 
       let(:data) { valid_data }
 
       it { should be_nil }
 
-      context "with an existing patient in a cohort" do
-        let(:patient) { create(:patient, nhs_number:, cohort: create(:cohort)) }
+      context "with an existing patient in the cohort" do
+        let(:patient) { create(:patient, nhs_number:) }
 
-        it { should eq(patient.cohort) }
+        it { should eq(patient.organisation) }
       end
     end
   end