Upgrade gitlab-sidekiq-fetcher to 0.5.4 for bug fix

Resolves reliability issues in kubernetes, where pids are not as unique
as they need to be to disambiguate between restarts of the same
container (see https://gitlab.com/gitlab-org/sidekiq-reliable-fetch/-/issues/28)

Gemfile

@@ -196,7 +196,7 @@ gem 'acts-as-taggable-on', '~> 7.0'
 gem 'sidekiq', '~> 5.2.7'
 gem 'sidekiq-cron', '~> 1.0'
 gem 'redis-namespace', '~> 1.7.0'
-gem 'gitlab-sidekiq-fetcher', '0.5.3', require: 'sidekiq-reliable-fetch'
+gem 'gitlab-sidekiq-fetcher', '0.5.4', require: 'sidekiq-reliable-fetch'
 
 # Cron Parser
 gem 'fugit', '~> 1.2.1'

Gemfile.lock

@@ -451,7 +451,7 @@ GEM
     gitlab-pry-byebug (3.9.0)
       byebug (~> 11.0)
       pry (~> 0.13.0)
-    gitlab-sidekiq-fetcher (0.5.3)
+    gitlab-sidekiq-fetcher (0.5.4)
       sidekiq (~> 5)
     gitlab-styles (6.0.0)
       rubocop (~> 0.91.1)
@@ -1379,7 +1379,7 @@ DEPENDENCIES
   gitlab-markup (~> 1.7.1)
   gitlab-net-dns (~> 0.9.1)
   gitlab-pry-byebug
-  gitlab-sidekiq-fetcher (= 0.5.3)
+  gitlab-sidekiq-fetcher (= 0.5.4)
   gitlab-styles (~> 6.0.0)
   gitlab_chronic_duration (~> 0.10.6.2)
   gitlab_omniauth-ldap (~> 2.1.1)