Change the project runtime version from net7 to net6.

src/TensorflowNET.Hub/Tensorflow.Hub.csproj

@@ -1,8 +1,8 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;net6;net7</TargetFrameworks>
-    <LangVersion>11</LangVersion>
+    <TargetFrameworks>netstandard2.0;net6</TargetFrameworks>
+    <LangVersion>10</LangVersion>
     <Nullable>enable</Nullable>
   </PropertyGroup>
 

test/TensorflowNET.Hub.Unittest/Tensorflow.Hub.Unittest.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net7</TargetFramework>
+    <TargetFramework>net6</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>