require logger.gem and ostruct.gem since Ruby 3.5

warning: logger was loaded from the standard library, but will no longer be part of the default gems starting from Ruby 3.5.0.

Author: mvidner

ruby-dbus.gemspec

@@ -22,6 +22,7 @@ GEMSPEC = Gem::Specification.new do |s|
 
   s.required_ruby_version = ">= 2.4.0"
 
+  s.add_runtime_dependency "logger" if RUBY_VERSION >= "3.5"
   # Either of rexml and nokogiri is required
   # but AFAIK gemspec cannot express that.
   # Nokogiri is recommended as rexml is dead slow.
@@ -30,6 +31,7 @@ GEMSPEC = Gem::Specification.new do |s|
 
   # workaround: rubocop-1.0 needs base64 which is no longer in stdlib in newer rubies
   s.add_development_dependency "base64"
+  s.add_development_dependency "ostruct" if RUBY_VERSION >= "3.5"
   s.add_development_dependency "packaging_rake_tasks"
   s.add_development_dependency "rake"
   s.add_development_dependency "rspec", "~> 3"