fix: add Active Support as runtime dependency in Racecar instrumentation

Installation of Racecar instrumentation silently fails without Active Support. Since this instrumentation doesn’t work at all without Active Support, it should be listed as a runtime dependency.

It was already being installed in test and example Gemfiles.

Author: razumau

instrumentation/racecar/opentelemetry-instrumentation-racecar.gemspec

@@ -25,6 +25,7 @@ Gem::Specification.new do |spec|
   spec.require_paths = ['lib']
   spec.required_ruby_version = ">= #{File.read(File.expand_path('../../gemspecs/RUBY_REQUIREMENT', __dir__))}"
 
+  spec.add_dependency 'activesupport'
   spec.add_dependency 'opentelemetry-api', '~> 1.0'
   spec.add_dependency 'opentelemetry-instrumentation-base', '~> 0.23.0'