update uptime ips url (#15722)

ref: getsentry/sentry#104305

Author: lynnagara

docs/security-legal-pii/security/ip-ranges.mdx

@@ -149,7 +149,7 @@ Sentry uses the following IP addresses for uptime checks for all regions:
 For the most up-to-date list of Uptime Monitoring IP addresses, you can query the following API endpoint:
 
 ```plaintext
-https://us.sentry.io/api/0/uptime-ips/
+https://sentry.io/api/0/uptime-ips/
 ```
 
 This endpoint returns a newline-separated list of all current Uptime Monitoring IP addresses (for all regions) that can be programmatically processed in your allowlist configurations.