Merge pull request #4481 from DataDog/fix-leaking-thread-detection-for-connection-reaper

[NO-TICKET] Adjust leaking thread detection for new Rails

Author: Strech

spec/spec_helper.rb

@@ -159,7 +159,7 @@
           # WEBrick server thread
           t[:WEBrickSocket] ||
           # Rails connection reaper
-          backtrace.find { |b| b.include?('lib/active_record/connection_adapters/abstract/connection_pool.rb') } ||
+          backtrace.find { |b| b =~ %r{lib/active_record/connection_adapters/abstract/connection_pool(/reaper)?.rb} } ||
           # Ruby JetBrains debugger
           (t.class.name && t.class.name.include?('DebugThread')) ||
           # Categorized as a known leaky thread