Disable the reporter before exiting to avoid "UnexpectedExit" error.

PiperOrigin-RevId: 895911905

fuzztest/internal/runtime.cc

diff --git a/fuzztest/internal/runtime.cc b/fuzztest/internal/runtime.cc
index cee5f50..f03dbaf 100644
--- a/fuzztest/internal/runtime.cc
+++ b/fuzztest/internal/runtime.cc
@@ -802,6 +802,7 @@
         counter = 0;
       }
     }
+    runtime_.DisableReporter();
     std::exit(130);  // Exit code termination.
   }