TShock: bump .NET version to 9

Author: Greelan

tshockconfig.json

@@ -2471,15 +2471,15 @@
         "DisplayName": "Dotnet Version",
         "Category": "Updates",
         "Subcategory": "Runtime Configuration:build:3",
-        "Description": "Sets the [ASP.NET Core Runtime 6.0 version](https://dotnet.microsoft.com/en-us/download/dotnet/6.0) to install for TShock. Empty = latest. NOTE: Update the server after switching versions!",
+        "Description": "Sets the [ASP.NET Core Runtime 9.0 version](https://dotnet.microsoft.com/en-us/download/dotnet/9.0) to install for TShock. Empty = latest. NOTE: Update the server after switching versions!",
         "Keywords": "dotnet,version",
         "FieldName": "DotnetVersion",
         "InputType": "text",
         "IsFlagArgument": false,
         "ParamFieldName": "DotnetVersion",
         "IncludeInCommandLine": false,
         "DefaultValue": "",
-        "Placeholder": "6.0.22",
+        "Placeholder": "9.0.13",
         "EnumValues": {}
     },
     {