fix flaky CreateOutcomeProficiency mutation specs

fixes DE-254
flag = none

Test Plan:
 - tests pass 100%

Change-Id: Ic74ad73f09c1344b4cffa9223298e5fe33065e61
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/247330
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Aaron Ogata <aogata@instructure.com>
QA-Review: Ryan Norton <rnorton@instructure.com>
Product-Review: Ryan Norton <rnorton@instructure.com>

spec/graphql/mutations/create_outcome_proficiency_spec.rb

@@ -27,6 +27,13 @@ describe Mutations::CreateOutcomeProficiency do
     @teacher = @course.enroll_teacher(User.create!, enrollment_state: 'active').user
   end
 
+  let(:audit_log_field_extension) { class_double(AuditLogFieldExtension).as_stubbed_const }
+
+  before(:each) do
+    # prevent unnecessary calls to dynamo (audit logs)
+    allow(audit_log_field_extension).to receive(:enabled?).and_return false
+  end
+
   def execute_with_input(create_input, user_executing: @admin)
     mutation_command = <<~GQL
       mutation {