ref: Rails 7 Healthcheck endpoint (#11505)

getsentry/relay#4117

Author: HazAT

docs/concepts/data-management/filtering/index.mdx

@@ -61,6 +61,7 @@ We consider a transaction to be a health check if its name matches one of the fo
 - `*/ready`
 - `*/readyz`
 - `*/ping`
+- `*/up`
 
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