fix: replace deprecated TestContext with BunitContext

test/Blog.Tests/Unit/Feed.spec.razor

@@ -1,4 +1,4 @@
-@inherits Bunit.TestContext
+@inherits Bunit.BunitContext
 
 @code
 {
@@ -11,7 +11,7 @@
     .Setup(x => x.GetPostsAsync())
     .ReturnsAsync(new List<Post>());
 
-    var ctx = new TestContext();
+    var ctx = new BunitContext();
 
     ctx.Services.AddSingleton(_postServiceMock.Object);
 
@@ -32,7 +32,7 @@
     .Setup(x => x.GetPostsAsync())
     .ReturnsAsync(posts);
 
-    var ctx = new TestContext();
+    var ctx = new BunitContext();
 
     ctx.Services.AddScoped(_ => _postServiceMock.Object);
 

test/Blog.Tests/Unit/Footer.spec.razor

@@ -1,11 +1,11 @@
-@inherits Bunit.TestContext
+@inherits Bunit.BunitContext
 
 @code
 {
   [Test]
   public void Footer_WhenRendered_ItShouldRenderFooterWithNavLinks()
   {
-    var ctx = new TestContext();
+    var ctx = new BunitContext();
 
     var cut = ctx.Render(@<Footer />);
 

test/Blog.Tests/Unit/Header.spec.razor

@@ -1,4 +1,4 @@
-@inherits Bunit.TestContext
+@inherits Bunit.BunitContext
 
 @code
 {