refactor(NetworkMonitor): add try/finally keep release simaphore slim (#6496)

Author: ArgoZhang

src/BootstrapBlazor/Services/DefaultNetworkMonitorService.cs

@@ -58,16 +58,22 @@ public async Task RegisterStateChangedCallback(IComponent component, Func<Networ
             await _semaphoreSlim.WaitAsync(3000);
             if (!_init)
             {
-                _init = true;
+                try
+                {
+                    _init = true;
 
-                _networkModule ??= await _runtime.LoadModuleByName("net");
-                await _networkModule.InvokeVoidAsync("init", new
+                    _networkModule ??= await _runtime.LoadModuleByName("net");
+                    await _networkModule.InvokeVoidAsync("init", new
+                    {
+                        Invoke = _interop,
+                        OnNetworkStateChangedCallback = nameof(TriggerNetworkStateChanged)
+                    });
+                }
+                finally
                 {
-                    Invoke = _interop,
-                    OnNetworkStateChangedCallback = nameof(TriggerNetworkStateChanged)
-                });
+                    _semaphoreSlim.Release();
+                }
             }
-            _semaphoreSlim.Release();
         }
     }