Update Cake to 4.0.0

dotnet-tools.json

@@ -3,16 +3,10 @@
   "isRoot": true,
   "tools": {
     "cake.tool": {
-      "version": "3.2.0",
+      "version": "4.0.0",
       "commands": [
         "dotnet-cake"
       ]
-    },
-    "dotnet-example": {
-      "version": "1.6.0",
-      "commands": [
-        "dotnet-example"
-      ]
     }
   }
 }