remove .net core 2.2 and 3.1 from tests

Author: Filip Staffa

.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:

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;net9.0;net10.0</TargetFrameworks>
+    <TargetFrameworks>net6.0;net8.0;net9.0;net10.0</TargetFrameworks>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.8.0" />