The current net-http is only works with Ruby 2.6+

lib/net/http/net-http.gemspec

@@ -13,7 +13,7 @@ Gem::Specification.new do |spec|
   spec.summary       = %q{HTTP client api for Ruby.}
   spec.description   = %q{HTTP client api for Ruby.}
   spec.homepage      = "https://github.com/ruby/net-http"
-  spec.required_ruby_version = Gem::Requirement.new(">= 2.3.0")
+  spec.required_ruby_version = Gem::Requirement.new(">= 2.6.0")
 
   spec.metadata["homepage_uri"] = spec.homepage
   spec.metadata["source_code_uri"] = spec.homepage