[Speed] Update run-speed-test.mdx (cloudflare#25494)

Per dashboard, "Enable RUM".

Thanks!

Author: nenizera

src/content/docs/speed/observatory/run-speed-test.mdx

@@ -32,7 +32,7 @@ In the Tested URLs table, in the last column, you can select the three dots > **
 
 Once a test has been run, you can enable RUM data in the test results page:
 
-1. Go to **Observatory** and select **Enable Rum**. You can choose to enable globally or enable everywhere except the EU.
+1. Go to **Observatory** and select **Enable RUM**. You can choose to enable globally or enable everywhere except the EU.
 2. Once RUM data is running on your site, you can access **Real user measurements** on your test results page. Usually it takes less than five minutes to see the data coming in, but it will depend on traffic.
 
 Refer to [Understand test results](/speed/observatory/test-results/) for more information about the results provided by real user data.