jobs with retry = false should not count towards dead jobs counter (#76)

jobs with retry = false should not count towards dead jobs counter (#76)

diff --git a/lib/prometheus_exporter/instrumentation/sidekiq.rb b/lib/prometheus_exporter/instrumentation/sidekiq.rb
index b25a2e8..e250005 100644
--- a/lib/prometheus_exporter/instrumentation/sidekiq.rb
+++ b/lib/prometheus_exporter/instrumentation/sidekiq.rb
@@ -4,11 +4,15 @@ module PrometheusExporter::Instrumentation
   class Sidekiq
     def self.death_handler
       -> (job, ex) do
-        PrometheusExporter::Client.default.send_json(
-          type: "sidekiq",
-          name: job["class"],
-          dead: true,
-        )
+        job_is_fire_and_forget = job["retry"] == false
+
+        unless job_is_fire_and_forget
+          PrometheusExporter::Client.default.send_json(
+            type: "sidekiq",
+            name: job["class"],
+            dead: true,
+          )
+        end
       end
     end

GitHub sha: 32a6bd1f