Promote stackprof into a production gem

stackprof and ruby-prof are complementary tools: the former is a
sampling profiler, and the latter is a tracing profiler. It would be
quite helpful to have stackprof available to profile endpoints in
production or on Omnibus.

Diff between v0.2.13 and v0.2.15:
https://github.com/tmm1/stackprof/compare/v0.2.13..v0.2.15

Closes https://gitlab.com/gitlab-org/gitlab/issues/199994

Gemfile

@@ -381,8 +381,6 @@ group :development, :test do
 
   gem 'knapsack', '~> 1.17'
 
-  gem 'stackprof', '~> 0.2.13', require: false
-
   gem 'simple_po_parser', '~> 1.1.2', require: false
 
   gem 'timecop', '~> 0.8.0'
@@ -427,6 +425,7 @@ gem 'email_reply_trimmer', '~> 0.1'
 gem 'html2text'
 
 gem 'ruby-prof', '~> 1.0.0'
+gem 'stackprof', '~> 0.2.15', require: false
 gem 'rbtrace', '~> 0.4', require: false
 gem 'memory_profiler', '~> 0.9', require: false
 gem 'benchmark-memory', '~> 0.1', require: false

Gemfile.lock

@@ -1037,7 +1037,7 @@ GEM
       sprockets (>= 3.0.0)
     sqlite3 (1.3.13)
     sshkey (2.0.0)
-    stackprof (0.2.13)
+    stackprof (0.2.15)
     state_machines (0.5.0)
     state_machines-activemodel (0.7.1)
       activemodel (>= 4.1)
@@ -1381,7 +1381,7 @@ DEPENDENCIES
   spring-commands-rspec (~> 1.0.4)
   sprockets (~> 3.7.0)
   sshkey (~> 2.0)
-  stackprof (~> 0.2.13)
+  stackprof (~> 0.2.15)
   state_machines-activerecord (~> 0.6.0)
   sys-filesystem (~> 1.1.6)
   test-prof (~> 0.10.0)

changelogs/unreleased/sh-promote-stackprof.yml

+---
+title: Promote stackprof into a production gem
+merge_request: 24564
+author:
+type: other