fix: remove active_model_serializers from releases.yml (#1326)

This was missed in the great -contrib migration, and causes the "Update
open releases" hook to fail on pushes to `main`.

Author: ahayworth

.toys/.data/releases.yml

@@ -62,10 +62,6 @@ gems:
     directory: exporter/zipkin
     version_constant: [OpenTelemetry, Exporter, Zipkin, VERSION]
 
-  - name: opentelemetry-instrumentation-active_model_serializers
-    directory: instrumentation/active_model_serializers
-    version_constant: [OpenTelemetry, Instrumentation, ActiveModelSerializers, VERSION]
-
   - name: opentelemetry-propagator-b3
     directory: propagator/b3
     version_constant: [OpenTelemetry, Propagator, B3, VERSION]