Remove parse_rows! call from process!

This is to make it easier to reason about the code: when parse_rows! is explicit
it's clear what stage of the process is executing when.

Jira-Issue: MAV-6063

Author: misaka

app/jobs/process_import_job.rb

@@ -6,11 +6,14 @@ class ProcessImportJob < ApplicationJob
   queue_as :imports
 
   def perform(import)
+    return if import.processed?
+
     SemanticLogger.tagged(import_id: import.id) do
       Sentry.set_tags(import_id: import.id)
 
       import.parse_rows!
 
+      return if import.invalid?
       return if import.rows_are_invalid?
 
       import.process!

app/models/concerns/csv_importable.rb

@@ -146,11 +146,6 @@ def processed?
   end
 
   def process!
-    return if processed?
-
-    parse_rows! if rows.nil?
-    return if invalid?
-
     process_import!
 
     TeamCachedCounts.new(team).reset_import_issues!

spec/controllers/api/testing/teams_controller_spec.rb

@@ -47,6 +47,7 @@
         create(:session, team:, location: team.gias_schools.first, programmes:)
 
       process_and_approve_import(cohort_import)
+      immunisation_import.parse_rows!
       immunisation_import.process!
 
       Patient.find_each do |patient|

spec/models/class_import_spec.rb

@@ -142,6 +142,8 @@
         queue: :imports
       ).and_return(configured_job)
       allow(configured_job).to receive(:perform_later)
+
+      class_import.parse_rows!
     end
 
     context "when pds_search_during_import flag is enabled" do

spec/models/cohort_import_spec.rb

@@ -143,6 +143,8 @@
         queue: :imports
       ).and_return(configured_job)
       allow(configured_job).to receive(:perform_later)
+
+      cohort_import.parse_rows!
     end
 
     context "when pds_search_during_import flag is enabled" do

spec/models/immunisation_import_spec.rb

@@ -197,6 +197,8 @@
     before do
       Flipper.enable(:pds)
       Flipper.enable(:pds_enqueue_bulk_updates)
+
+      immunisation_import.parse_rows!
     end
 
     let(:duplicate_import) do

spec/support/imports_helper.rb

@@ -47,6 +47,7 @@ def perform_enqueued_jobs_while_exists(only:)
   # Process and approve an import programmatically (for job/unit specs)
   # This simulates the full import flow including review and approval
   def process_and_approve_import(import)
+    import.parse_rows!
     import.process!
 
     unless import.is_a?(ImmunisationImport)

spec/support/shared_examples/a_csv_importable_model.rb

@@ -91,6 +91,8 @@
   describe "#process!" do
     let(:today) { Time.zone.local(2025, 6, 1) }
 
+    before { subject.parse_rows! }
+
     # TODO: Remove if ... when ImmunisationImport's implementation has been
     #       updated to match the others (i.e. it uses changesets)
     if described_class <= ImmunisationImport