Increase the number of attempts for gpg cleanup

By default Retriable would only try 3 times. Which would never hit our
limit of 10s in sidekiq. Raising the number of tries means we'll only
be limited by the maximum runtime.

lib/gitlab/gpg.rb

@@ -6,7 +6,7 @@ module Gitlab
 
     CleanupError = Class.new(StandardError)
     BG_CLEANUP_RUNTIME_S = 10
-    FG_CLEANUP_RUNTIME_S = 0.5
+    FG_CLEANUP_RUNTIME_S = 1
 
     MUTEX = Mutex.new
 
@@ -127,7 +127,10 @@ module Gitlab
       # error.
       # Failing to remove the tmp directory could leave the `gpg-agent` process
       # running forever.
-      Retriable.retriable(max_elapsed_time: cleanup_time, base_interval: 0.1) do
+      #
+      # 15 tries will never complete within the maximum time with exponential
+      # backoff. So our limit is the runtime, not the number of tries.
+      Retriable.retriable(max_elapsed_time: cleanup_time, base_interval: 0.1, tries: 15) do
         FileUtils.remove_entry(tmp_dir) if File.exist?(tmp_dir)
       end
     rescue => e

spec/lib/gitlab/gpg_spec.rb

@@ -208,8 +208,8 @@ describe Gitlab::Gpg do
         allow(FileUtils).to receive(:remove_entry).with(any_args).and_call_original
       end
 
-      it "tries for #{seconds}" do
-        expect(Retriable).to receive(:retriable).with(a_hash_including(max_elapsed_time: seconds))
+      it "tries for #{seconds} or 15 times" do
+        expect(Retriable).to receive(:retriable).with(a_hash_including(max_elapsed_time: seconds, tries: 15))
 
         described_class.using_tmp_keychain {}
       end