Add specific targets for .NET8 to core and automapper

Author: kzu

src/Merq.AutoMapper/Merq.AutoMapper.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net6.0;net472</TargetFrameworks>
+    <TargetFrameworks>net6.0;net8.0;net472</TargetFrameworks>
     <PackageId>Merq.AutoMapper</PackageId>
     <Title>A specialized Message Bus that allows cross observing and executing of events and commands from structurally compatible types even if they are from disparate assemblies, as long as their full name is the same, otherwise known as "duck typing".</Title>
     <Description>$(Title)</Description>

src/Merq/Merq.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;net6.0</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;net6.0;net8.0</TargetFrameworks>
     <PackageId>Merq</PackageId>
     <Title>
       Merq: Message Bus (Commands + Events) mediator for internal application architecture via command and event messages.