chore(ruby): Remove enable_tracing (#12601)

Author: sl0thentr0py

docs/platforms/ruby/common/configuration/options.mdx

@@ -233,7 +233,7 @@ A number between 0 and 1 that determines the percentage of total transaction tha
 
 If <PlatformIdentifier name="traces-sample-rate" /> is set to 0, no new traces will be created. However, if you have another service (for example a JS frontend) that makes requests to your service and has trace information, those traces will be continued and transactions will be sent to Sentry.
 
-To disable all tracing, you'll either need to set <PlatformIdentifier name="traces-sample-rate" />`=None` or set <PlatformIdentifier name="enable-tracing" />`=False`. Once this is done, no new traces will be started and no incoming traces will be continued.
+To disable all tracing, you'll need to set <PlatformIdentifier name="traces-sample-rate" />` = nil`. Once this is done, no new traces will be started and no incoming traces will be continued.
 
 <PlatformContent includePath="performance/traces-sample-rate" />