Fix execution spec with cucumber on ruby 3.4

Cucumber is broken on ruby 3.4 currently, requires the fix in
cucumber/cucumber-ruby#1757
(not released yet).

Use their master from git on ruby 3.4 and unpend the test.

spec/datadog/core/environment/execution_spec.rb

@@ -173,7 +173,13 @@ def test_it_does_something_useful
 
             gemfile(true) do
               source 'https://rubygems.org'
-              gem 'cucumber', '>= 3'
+              if RUBY_VERSION >= '3.4'
+                # Cucumber is broken on Ruby 3.4, requires the fix in
+                # https://github.com/cucumber/cucumber-ruby/pull/1757
+                gem 'cucumber', '>= 3', git: 'https://github.com/cucumber/cucumber-ruby'
+              else
+                gem 'cucumber', '>= 3'
+              end
             end
 
             load Gem.bin_path('cucumber', 'cucumber')
@@ -192,8 +198,6 @@ def test_it_does_something_useful
                 Open3.capture3('ruby', stdin_data: script)
               end
 
-              # Ruby 3.4 outputs an exception instead of the information to be asserted because of the forked process.
-              pending('Pending for Ruby 3.4.') if RUBY_VERSION.start_with?('3.4.')
               expect(err).to include('ACTUAL:true')
             end
           end