Update HealthCheckService.xml (#8917)

Remove double '.'

Author: marco-olimpio

xml/Microsoft.Extensions.Diagnostics.HealthChecks/HealthCheckService.xml

@@ -92,7 +92,7 @@
         <returns>
             A <see cref="T:System.Threading.Tasks.Task`1" /> which will complete when all the health checks have been run,
             yielding a <see cref="T:Microsoft.Extensions.Diagnostics.HealthChecks.HealthReport" /> containing the results.
-          .</returns>
+        </returns>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>