Upgrade to .NET 8 since .NET 6 is past EOL

Author: andyleejordan

Diff for: .pipelines/PSScriptAnalyzer-Official.yml

@@ -80,10 +80,7 @@ extends:
             inputs:
               packageType: sdk
               useGlobalJson: true
-          - pwsh: |
-              Register-PSRepository -Name CFS -SourceLocation "https://pkgs.dev.azure.com/powershell/PowerShell/_packaging/powershell/nuget/v2" -InstallationPolicy Trusted
-              Install-Module -Repository CFS -Name Microsoft.PowerShell.PSResourceGet
-              ./tools/installPSResources.ps1 -PSRepository CFS
+          - pwsh: ./tools/installPSResources.ps1 -PSRepository CFS
             displayName: Install PSResources
           - pwsh: ./build.ps1 -Configuration Release -All
             displayName: Build

Diff for: Engine/Engine.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <VersionPrefix>$(ModuleVersion)</VersionPrefix>
-    <TargetFrameworks>net6;net462</TargetFrameworks>
+    <TargetFrameworks>net8;net462</TargetFrameworks>
     <AssemblyName>Microsoft.Windows.PowerShell.ScriptAnalyzer</AssemblyName>
     <AssemblyVersion>$(ModuleVersion)</AssemblyVersion>
     <PackageId>Engine</PackageId>

Diff for: Rules/Rules.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <VersionPrefix>$(ModuleVersion)</VersionPrefix>
-    <TargetFrameworks>net6;net462</TargetFrameworks>
+    <TargetFrameworks>net8;net462</TargetFrameworks>
     <AssemblyName>Microsoft.Windows.PowerShell.ScriptAnalyzer.BuiltinRules</AssemblyName>
     <AssemblyVersion>$(ModuleVersion)</AssemblyVersion>
     <PackageId>Rules</PackageId>

Diff for: global.json

@@ -1,5 +1,6 @@
 {
     "sdk": {
-        "version": "6.0.427"
+        "version": "8.0.406",
+        "rollForward": "latestFeature"
     }
 }