Use .NET 6 for CI build and test

Author: dbrattli

Build.fsproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net5.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="Helpers.fs" />

paket.dependencies

@@ -2,7 +2,7 @@
 
 source https://api.nuget.org/v3/index.json
 storage: none
-framework: net5.0, netstandard2.0, netstandard2.1
+framework: net6.0, netstandard2.0, netstandard2.1
 
 nuget FSharp.Core ~> 4.7
 nuget Fable.Core.Experimental >= 4.0.0-alpha-013
@@ -22,7 +22,7 @@ group Test
 group Build
     source https://api.nuget.org/v3/index.json
     storage: none
-    framework: net5.0
+    framework: net6.0
 
     nuget Fake.Core.Target
     nuget Fake.IO.FileSystem

paket.lock

@@ -1,13 +1,13 @@
 STORAGE: NONE
-RESTRICTION: || (== net5.0) (== netstandard2.0) (== netstandard2.1)
+RESTRICTION: || (== net6.0) (== netstandard2.0) (== netstandard2.1)
 NUGET
   remote: https://api.nuget.org/v3/index.json
     Fable.Core.Experimental (4.0.0-alpha-013)
     FSharp.Core (4.7.2)
 
 GROUP Build
 STORAGE: NONE
-RESTRICTION: == net5.0
+RESTRICTION: == net6.0
 NUGET
   remote: https://api.nuget.org/v3/index.json
     Fake.Core.CommandLineParsing (5.20.4)
@@ -54,9 +54,7 @@ NUGET
       System.Reactive (>= 5.0)
     FSharp.Core (6.0.1)
     System.Collections.Immutable (6.0)
-      System.Memory (>= 4.5.4)
       System.Runtime.CompilerServices.Unsafe (>= 6.0)
-    System.Memory (4.5.4)
     System.Reactive (5.0)
     System.Runtime.CompilerServices.Unsafe (6.0)