chore: removes net7.0 support

It is no longer supported

Author: billrob

src/CsvHelper/CsvHelper.csproj

@@ -8,7 +8,7 @@
 
 		<!-- Build -->
 		<AssemblyName>CsvHelper</AssemblyName>
-		<TargetFrameworks>net8.0;net7.0;net6.0;netstandard2.1;netstandard2.0;net48;net47;net462</TargetFrameworks>
+		<TargetFrameworks>net8.0;net6.0;netstandard2.1;netstandard2.0;net48;net47;net462</TargetFrameworks>
 		<!--<TargetFrameworks>net60</TargetFrameworks>-->
 		<LangVersion>latest</LangVersion>
 		<RootNamespace>CsvHelper</RootNamespace>

src/CsvHelper/CsvHelper.net7.0.v3.ncrunchproject

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
 	<PropertyGroup>
-		<TargetFrameworks>net8.0;net7.0;net6.0;net48;net47;net462</TargetFrameworks>
+		<TargetFrameworks>net8.0;net6.0;net48;net47;net462</TargetFrameworks>
 		<!--<TargetFrameworks>net8.0</TargetFrameworks>-->
 		<LangVersion>preview</LangVersion>
 		<SignAssembly>True</SignAssembly>