OCPBUGS-60273: Ensure revision.json persists on ungraceful shutdown

Add os.O_SYNC flag to OpenFile call in trySaveRevision to force
synchronous writes to disk. This prevents the revision.json file from
being empty if the process terminates unexpectedly before buffered data
is flushed.

Author: clobrano

pkg/cmd/rev/rev.go

@@ -189,7 +189,7 @@ func trySaveRevision(ctx context.Context, endpoints []string, outputFile string,
 	}
 
 	tmpPath := fmt.Sprintf("%s.tmp", outputFile)
-	file, err := os.OpenFile(tmpPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644)
+	file, err := os.OpenFile(tmpPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC|os.O_SYNC, 0644)
 	if err != nil {
 		klog.Errorf("error opening file: %v", err)
 		return