switch to t4 cli, update country definitions to correspond to code

.config/dotnet-tools.json

@@ -0,0 +1,12 @@
+{
+  "version": 1,
+  "isRoot": true,
+  "tools": {
+    "dotnet-t4": {
+      "version": "3.0.0",
+      "commands": [
+        "t4"
+      ]
+    }
+  }
+}

.github/workflows/dotnetcore.yml

@@ -13,14 +13,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - name: Setup .NET Core 2.2
-        uses: actions/setup-dotnet@v3
-        with:
-          dotnet-version: 2.2.x
-      - name: Setup .NET Core 3.1
-        uses: actions/setup-dotnet@v3
-        with:
-          dotnet-version: 3.1.x
       - name: Setup .NET 6
         uses: actions/setup-dotnet@v3
         with:
@@ -29,6 +21,20 @@ jobs:
         uses: actions/setup-dotnet@v3
         with:
           dotnet-version: 8.0.x
+      - name: Setup .NET 9
+        uses: actions/setup-dotnet@v3
+        with:
+          dotnet-version: 9.0.x
+      - name: Setup .NET 10
+        uses: actions/setup-dotnet@v3
+        with:
+          dotnet-version: 10.0.x
+      - name: Restore dotnet tools
+        run: dotnet tool restore
+      - name: Regenerate from T4
+        run: dotnet t4 src/PostalCodes/Generated/PostalCodeFactory.gen.tt
+      - name: Verify no drift
+        run: git diff --exit-code
       - name: Build with dotnet
         run: dotnet build --configuration Release /p:ContinuousIntegrationBuild=true
       - name: Test

src/PostalCodes.UnitTests/PostalCodes.UnitTests.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.2;netcoreapp3.1;net6.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net6.0;net8.0;net9.0;net10.0</TargetFrameworks>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.8.0" />