use not-eol target frameworks

Author: zachrybaker

example/Sample/Sample.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net48;net5.0</TargetFrameworks>
+    <TargetFrameworks>net48;net6.0</TargetFrameworks>
     <LangVersion>8.0</LangVersion>
     <Nullable>enable</Nullable>
     <AssemblyName>Sample</AssemblyName>

src/Serilog.Sinks.File/Serilog.Sinks.File.csproj

@@ -4,7 +4,7 @@
     <Description>Write Serilog events to text files in plain or JSON format.</Description>
     <VersionPrefix>5.0.1</VersionPrefix>
     <Authors>Serilog Contributors</Authors>
-    <TargetFrameworks>net45;netstandard1.3;netstandard2.0;netstandard2.1;net5.0</TargetFrameworks>
+    <TargetFrameworks>net45;netstandard1.3;netstandard2.0;netstandard2.1;net6.0;net7.0</TargetFrameworks>
     <LangVersion>8.0</LangVersion>
     <Nullable>enable</Nullable>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>

test/Serilog.Sinks.File.Tests/Serilog.Sinks.File.Tests.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
 
-    <TargetFrameworks>net48;net5.0</TargetFrameworks>
+    <TargetFrameworks>net48;net6.0</TargetFrameworks>
     <LangVersion>8.0</LangVersion>
     <Nullable>enable</Nullable>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>