fix: LoggingSpanExporter and LoggingMetricExporter flush() always returns success

LoggingSpanExporter.flush() and LoggingMetricExporter.flush() unconditionally
return success even if underlying handlers fail. This masks errors from the
caller.

Fixes #8360

Author: ADITYA-CODE-SOURCE

exporters/logging/src/main/java/io/opentelemetry/exporter/logging/LoggingMetricExporter.java

@@ -92,7 +92,7 @@ public CompletableResultCode flush() {
         return resultCode.fail();
       }
     }
-    return resultCode.succeed();
+    return resultCode;
   }
 
   @Override

exporters/logging/src/main/java/io/opentelemetry/exporter/logging/LoggingSpanExporter.java

@@ -82,7 +82,7 @@ public CompletableResultCode flush() {
         resultCode.fail();
       }
     }
-    return resultCode.succeed();
+    return resultCode;
   }
 
   @Override