Update to .NET 8.0 (#2566)

* Bumped up to LTS version, .NET 8.0

* Bumped up dependencies

* Rolled back dependency versions to 8

Signed-off-by: Zafer Balkan <[email protected]>

* Rolled back NET8_0_OR_GREATER

Signed-off-by: Zafer Balkan <[email protected]>

* Fixed newline issue

---------

Signed-off-by: Zafer Balkan <[email protected]>

Author: zbalkan

Directory.Packages.props

@@ -20,18 +20,18 @@
     <!-- external dependencies -->
     <PackageVersion Include="ApprovalTests" Version="7.0.0-beta.3" />
     <PackageVersion Include="BenchmarkDotNet" Version="0.13.1" />
-    <PackageVersion Include="AwesomeAssertions" Version="8.0.2" />
+    <PackageVersion Include="AwesomeAssertions" Version="8.1.0" />
     <PackageVersion Include="Microsoft.CSharp" Version="4.7.0" />
     <PackageVersion Include="Microsoft.DotNet.PlatformAbstractions" Version="3.1.6" />
-    <PackageVersion Include="Newtonsoft.Json" Version="13.0.2" />
-    <PackageVersion Include="System.Memory" Version="4.5.4" />
-    <PackageVersion Include="system.reactive.core" Version="5.0.0" />
+    <PackageVersion Include="Newtonsoft.Json" Version="13.0.3" />
+    <PackageVersion Include="System.Memory" Version="4.6.3" />
+    <PackageVersion Include="system.reactive.core" Version="6.0.0" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(DisableArcade)' == '1'">
     <!-- The xunit version should be kept in sync with the one that Arcade promotes -->
     <PackageVersion Include="xunit" Version="2.4.2" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="2.4.3" />
   </ItemGroup>
-  
-</Project>
+
+</Project>

src/System.CommandLine.Tests/CompletionTests.cs

@@ -784,12 +784,12 @@ public void When_parsing_from_text_if_the_proximate_option_is_completed_then_com
         {
             var command = new RootCommand
             {
-                CreateOptionWithAcceptOnlyFromAmong(name: "--framework", "net7.0"),
+                CreateOptionWithAcceptOnlyFromAmong(name: "--framework", "net8.0"),
                 CreateOptionWithAcceptOnlyFromAmong(name: "--language", "C#"),
                 new Option<string>("--langVersion")
             };
             var configuration = new CommandLineConfiguration(command);
-            var completions = command.Parse("--framework net7.0 --l", configuration).GetCompletions();
+            var completions = command.Parse("--framework net8.0 --l", configuration).GetCompletions();
 
             completions.Select(item => item.Label)
                        .Should()
@@ -801,12 +801,12 @@ public void When_parsing_from_array_if_the_proximate_option_is_completed_then_co
         {
             var command = new RootCommand
             {
-                CreateOptionWithAcceptOnlyFromAmong(name: "--framework", "net7.0"),
+                CreateOptionWithAcceptOnlyFromAmong(name: "--framework", "net8.0"),
                 CreateOptionWithAcceptOnlyFromAmong(name: "--language", "C#"),
                 new Option<string>("--langVersion")
             };
             var configuration = new CommandLineConfiguration(command);
-            var completions = command.Parse(new[]{"--framework","net7.0","--l"}, configuration).GetCompletions();
+            var completions = command.Parse(new[]{"--framework","net8.0","--l"}, configuration).GetCompletions();
 
             completions.Select(item => item.Label)
                        .Should()