squash: Abandon all hope ye who perform_start

instrumentation/active_job/lib/opentelemetry/instrumentation/active_job/subscriber.rb

@@ -106,14 +106,11 @@ def initialize(...)
           mapper = AttributeMapper.new
           default_handler = DefaultHandler.new(tracer, mapper)
           enqueue_handler = EnqueueHandler.new(tracer, mapper)
-          # Rails 7 uses `perform` as the ingress point to the job
-          # Rails 6 uses `perform_start` as the ingress point of the job
-          consumer_event = Gem::Requirement.create('< 7').satisfied_by?(::ActiveJob.version) ? 'perform_start.active_job' : 'perform.active_job'
 
           @handlers_by_pattern = {
             'enqueue.active_job' => enqueue_handler,
             'enqueue_at.active_job' => enqueue_handler,
-            consumer_event => PerformHandler.new(tracer, mapper)
+            'perform.active_job' => PerformHandler.new(tracer, mapper)
           }
           @handlers_by_pattern.default = default_handler
         end
@@ -122,7 +119,11 @@ def initialize(...)
         def enqueue_at(...); end
         def enqueue(...); end
         def enqueue_retry(...); end
-        def perform_start(...); end
+        # This event causes much heartache as it is the first in a series of events that is triggered.
+        # It should not be the ingress span because it does not measure anything.
+        # https://github.com/rails/rails/blob/v6.1.7.6/activejob/lib/active_job/instrumentation.rb#L14
+        # https://github.com/rails/rails/blob/v7.0.8/activejob/lib/active_job/instrumentation.rb#L19
+        # def perform_start(...); end
         def perform(...); end
         def retry_stopped(...); end
         def discard(...); end