Add GlobalSignRoot CA R3 for rubygems.org in puppet-runtime

If you run the gem.bat command on windows without first running environment.bat then you'll get an SSL error as rubygems.org cert is signed by a different CA now GlobalSignRootCA R3. This is an issue for bolt, pdk, etc.

We're already installing the old CA in GlobalSignRootCA.pem (https://github.com/puppetlabs/puppet-runtime/blob/master/resources/files/rubygems/GlobalSignRootCA.pem), but we should add the new one too.

The reason it's not an issue when first running environment.bat is because that script sets SSL_CERT_FILE etc to be the puppet-ca-bundle installed in puppet-agent, which includes the R3 cert.

See https://github.com/rubygems/rubygems/commit/2f8a3cf71a6a4737731f963f7ad71bf4954743ea#diff-4390e37145d27f817fe6e22497c15763540cb2e1e286b799e3c07491317ee665
and
https://github.com/rubygems/rubygems/commit/f6408675a02edeb7a197b4ba529a8282d822f26d#diff-4390e37145d27f817fe6e22497c15763540cb2e1e286b799e3c07491317ee665