fix gemspec

- appease rubocop
- more fixes
  apparently i don't run all tests in all platforms locally

Steepfile

@@ -3,10 +3,14 @@ D = Steep::Diagnostic
 target :lib do
   signature "*.rbs"
 
+  # NOTE: All client-exposed methods/types should now have type signatures / rbs support
   check "lib/unleash/client.rb"
   check "lib/unleash/context.rb"
+  check "lib/unleash/variant.rb"
   check "lib/unleash/scheduled_executor.rb"
 
+  # TODO: add signatures to the rest
+  # Mostly internal SDK files.
   ignore "lib/unleash/bootstrap"
   ignore "lib/unleash/strategy/*.rb"
   ignore "lib/unleash/util"

unleash-client.gemspec

@@ -40,6 +40,11 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "simplecov", "~> 0.21.2"
   spec.add_development_dependency "simplecov-lcov", "~> 0.8.0"
 
-  spec.add_development_dependency "rbs", "~> 2.7"
-  spec.add_development_dependency "steep", "~> 1.2"
+  # NOTE: only require rbs/steep in supported ruby versions. In EOL ruby/jruby, just ignore.
+  # rubocop:disable Gemspec/RubyVersionGlobalsUsage
+  if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('2.6') && RUBY_ENGINE != 'jruby'
+    spec.add_development_dependency "rbs", "~> 2.8"
+    spec.add_development_dependency "steep", "~> 1.3"
+  end
+  # rubocop:enable Gemspec/RubyVersionGlobalsUsage
 end