fix: gracefully handle process metrics registration failure on unsupported OSes

.chloggen/fix-aix-crash.yaml

@@ -0,0 +1,5 @@
+change_logs:
+  - change_type: bug_fix
+    component: opentelemetry-collector
+    note: "Fix panic in process metrics on unsupported OSes (e.g. AIX)"
+    issues: [14307]

service/service.go

@@ -234,9 +234,14 @@
 		return nil, err
 	}
 
-	if err := proctelemetry.RegisterProcessMetrics(srv.telemetrySettings); err != nil {
-		return nil, fmt.Errorf("failed to register process metrics: %w", err)
-	}
+	// Only register process metrics on supported OSes.
+    // AIX is currently unsupported for process metrics, so we skip it to avoid crashing.
+    // For other OSes, we want to fail fast if registration fails.
+    if runtime.GOOS != "aix" {
+        if err := proctelemetry.RegisterProcessMetrics(srv.telemetrySettings); err != nil {
+            return nil, err
+        }
+    }
 	return srv, nil
 }