drop support for net461, netcoreapp3.1 and net5.0, which are eol

Author: matracey

.github/workflows/build-and-test.yaml

@@ -11,7 +11,7 @@ jobs:
     strategy:
       matrix:
         build-configuration: [ Debug, Release ]
-        test-target-framework: [ net6.0, net5.0, netcoreapp3.1 ]
+        test-target-framework: [ net6.0 ]
     name: Build And Test (${{ matrix.test-target-framework }}, ${{ matrix.build-configuration }})
     runs-on: ubuntu-latest
     steps:
@@ -21,8 +21,6 @@ jobs:
         with:
           dotnet-version: |
             6.x
-            5.x
-            3.1.x
       - name: Restore
         run: dotnet restore ${{ env.JsonDiffPatchSolutionPath }}
       - name: Build

src/Directory.Build.props

@@ -1,7 +1,7 @@
 <Project>
 
     <PropertyGroup>
-        <TargetFrameworks>netstandard2.0;netstandard2.1;net461</TargetFrameworks>
+        <TargetFrameworks>netstandard2.0;netstandard2.1</TargetFrameworks>
         <Nullable>enable</Nullable>
         <LangVersion>latest</LangVersion>
         <GenerateDocumentationFile>true</GenerateDocumentationFile>

src/SystemTextJson.JsonDiffPatch/SystemTextJson.JsonDiffPatch.csproj

@@ -18,10 +18,6 @@
         <PackageReference Include="System.Text.Json" Version="6.0.0" />
     </ItemGroup>
 
-    <ItemGroup Condition="'$(TargetFramework)' == 'net461'">
-        <Reference Include="System.Web" />
-    </ItemGroup>
-
     <ItemGroup>
         <Compile Remove="JsonBytes.cs" />
         <None Include="JsonBytes.cs" />

test/Directory.Build.props

@@ -1,7 +1,7 @@
 <Project>
 
     <PropertyGroup>
-        <TargetFrameworks>netcoreapp3.1;net5.0;net6.0;net461;net48</TargetFrameworks>
+        <TargetFrameworks>net48;net6.0</TargetFrameworks>
     </PropertyGroup>
 
     <PropertyGroup>