remove migration guide entry

Author: msonnb

MIGRATION.md

@@ -254,16 +254,6 @@ Affected SDKs: All SDKs.
 
 If you reference these attributes in custom instrumentation, `beforeSendSpan`, dashboards, or alerts, update them to the new names.
 
-### Span operation changes
-
-Affected SDKs: All SDKs.
-
-Span operations (`sentry.op`) were aligned with the values defined in `@sentry/conventions`:
-
-- `@sentry/node`: Firebase Functions spans now use `function.gcp` instead of `http.request`. The wrapper instruments all function trigger types (HTTP, Firestore, scheduler, storage), so a fixed HTTP op was wrong. The trigger type remains available on the `faas.trigger` attribute.
-
-If you reference these operations in dashboards, alerts, or `beforeSendSpan`, update them to the new values.
-
 ### `thirdPartyErrorFilterIntegration` filters internal frames by default
 
 Affected SDKs: All SDKs.