Yield job to BackgroundMigration#steal predicate

lib/gitlab/background_migration.rb

@@ -33,7 +33,7 @@ module Gitlab
 
           next unless job.queue == self.queue
           next unless migration_class == steal_class
-          next if block_given? && !(yield migration_args)
+          next if block_given? && !(yield job)
 
           begin
             perform(migration_class, migration_args) if job.delete

spec/lib/gitlab/background_migration_spec.rb

@@ -55,7 +55,7 @@ RSpec.describe Gitlab::BackgroundMigration do
             expect(described_class).to receive(:perform)
               .with('Foo', [10, 20])
 
-            described_class.steal('Foo') { |(arg1, arg2)| arg1 == 10 && arg2 == 20 }
+            described_class.steal('Foo') { |job| job.args.second.first == 10 && job.args.second.second == 20 }
           end
 
           it 'does not steal jobs that do not match the predicate' do

spec/lib/gitlab/database/partitioning_migration_helpers/table_management_helpers_spec.rb

@@ -513,6 +513,7 @@ RSpec.describe Gitlab::Database::PartitioningMigrationHelpers::TableManagementHe
     context 'finishing pending background migration jobs' do
       let(:source_table_double) { double('table name') }
       let(:raw_arguments) { [1, 50_000, source_table_double, partitioned_table, source_column] }
+      let(:background_job) { double('background job', args: raw_arguments) }
 
       before do
         allow(migration).to receive(:table_exists?).with(partitioned_table).and_return(true)
@@ -528,7 +529,7 @@ RSpec.describe Gitlab::Database::PartitioningMigrationHelpers::TableManagementHe
 
         expect(Gitlab::BackgroundMigration).to receive(:steal)
           .with(described_class::MIGRATION_CLASS_NAME)
-          .and_yield(raw_arguments)
+          .and_yield(background_job)
 
         expect(source_table_double).to receive(:==).with(source_table.to_s)