RUBY-2452 OS name is linux on ruby-head (3.0) (#2138)

Co-authored-by: Oleg Pudeyev <oleg@bsdpower.com>

Author: p-mongo

spec/mongo/server/app_metadata_shared.rb

@@ -10,7 +10,7 @@
 
   it 'includes operating system information' do
     document[:client][:os][:type].should == 'linux'
-    if BSON::Environment.jruby?
+    if BSON::Environment.jruby? || RUBY_VERSION >= '3.0'
       document[:client][:os][:name].should == 'linux'
     else
       document[:client][:os][:name].should == 'linux-gnu'