Exclude system_tests group when running release prep in GH

When running in GH, don't install beaker gems and system_tests group, except for
the task acceptance case. That workflow already installs libcurl4 to work around
the faraday 1.x and patron issues. The GITHUB_WORKFLOW_REF contains the absolute
path to the workflow file, so we're not sensitive to the workflow name changing.

Author: joshcooper

Gemfile

@@ -61,6 +61,16 @@ group :development do
   gem "rubocop-ast", '< 1.43.0',                                                             require: false, platforms: [:mswin, :mingw, :x64_mingw]
   gem "rb-readline", '= 0.5.5',                                                              require: false, platforms: [:mswin, :mingw, :x64_mingw]
   gem "bigdecimal", '< 3.2.2',                                                               require: false, platforms: [:mswin, :mingw, :x64_mingw]
+end
+group :development, :release_prep do
+  gem "puppet-strings", '~> 4.0',         require: false
+  gem "puppetlabs_spec_helper", '~> 8.0', require: false
+  gem "puppet-blacksmith", '~> 7.0',      require: false
+end
+# On GitHub Actions, only resolve system_tests gems for the task_acceptance_tests
+# workflow to avoid native-extension (faraday-patron/libcurl4) failures in
+# workflows that don't need them (release_prep, unit_tests, static_code_analysis).
+unless ENV['GITHUB_ACTIONS'] && !ENV.fetch('GITHUB_WORKFLOW_REF', '').include?('task_acceptance_tests.yaml')
   gem "beaker", *location_for(ENV['BEAKER_VERSION'] || '~> 6.0')
   gem "beaker-abs", *location_for(ENV['BEAKER_ABS_VERSION'] || '~> 1.0')
   gem "beaker-hostgenerator", *location_for(ENV['BEAKER_HOSTGENERATOR_VERSION'] || '~> 2.0')
@@ -70,19 +80,14 @@ group :development do
   gem "beaker-puppet_install_helper",                                                        require: false
   gem "nokogiri",                                                                            require: false
   gem "beaker-task_helper", '~> 1.9',                                                        require: false if ENV["GEM_BOLT"]
-end
-group :development, :release_prep do
-  gem "puppet-strings", '~> 4.0',         require: false
-  gem "puppetlabs_spec_helper", '~> 8.0', require: false
-  gem "puppet-blacksmith", '~> 7.0',      require: false
-end
-# We are overriding the default PDK template's Litmus logic in order to use the
-# latest Bolt in tests. See PA-7824.
-group :system_tests do
-  gem "puppet_litmus", '~> 2.0',      require: false, platforms: [:ruby, :x64_mingw]
-  gem "CFPropertyList", '< 3.0.7',    require: false, platforms: [:mswin, :mingw, :x64_mingw]
-  gem "serverspec", '~> 2.41',        require: false
-  gem "voxpupuli-acceptance", '~> 3', require: false
+  # We are overriding the default PDK template's Litmus logic in order to use the
+  # latest Bolt in tests. See PA-7824.
+  group :system_tests do
+    gem "puppet_litmus", '~> 2.0',      require: false, platforms: [:ruby, :x64_mingw]
+    gem "CFPropertyList", '< 3.0.7',    require: false, platforms: [:mswin, :mingw, :x64_mingw]
+    gem "serverspec", '~> 2.41',        require: false
+    gem "voxpupuli-acceptance", '~> 3', require: false
+  end
 end
 
 gems = {}