Drop binding TFM from net7.0 to net6.0

Why: the 3.x binding's only net7-specific touchpoint is the
`Architecture.Arm64` enum (added in .NET Core 3.0 / netstandard 2.1).
Everything else (HttpClient, WebClient, WebProxy, Process, ACL APIs)
is available since netstandard 2.0 / net6.0.

Targeting net6.0 instead lets net6.0 SDK consumers stay on 3.x without
being forced to upgrade their runtime to net7+. .NET 5 and netcoreapp
3.1 still aren't covered — but per the SDK agent's 7-day BigQuery,
those TFMs have zero C# SDK traffic, so the practical impact is nil.

Net effect: removes the LOC-6563 rollout's hardest constraint
(forcing SDK to drop net6.0 from <TargetFrameworks> in order to
adopt 3.1.0). The 7 hard-blocked enterprise accounts on .NET 6.0.36
(group_id=934837 et al., 14 users, 623 weekly events) stay supported.

Also updates test project TFMs and HintPaths from net7.0 to net6.0
so the local build chain matches.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: yashdsaraf

BrowserStackLocal/BrowserStackLocal Unit Tests/BrowserStackLocal Unit Tests.csproj

@@ -2,7 +2,7 @@
   <PropertyGroup>
     <RootNamespace>BrowserStackLocal_Unit_Tests</RootNamespace>
     <AssemblyName>BrowserStackLocal Unit Tests</AssemblyName>
-    <TargetFrameworks>net7.0</TargetFrameworks>
+    <TargetFrameworks>net6.0</TargetFrameworks>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <Title>BrowserStackLocal Unit Tests</Title>
     <Product>BrowserStackLocal Unit Tests</Product>
@@ -18,10 +18,10 @@
     <PackageReference Include="NUnit3TestAdapter" Version="3.15.1" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.4.0" />
   </ItemGroup>
-  <ItemGroup Condition=" '$(TargetFramework)' == 'net7.0' ">
+  <ItemGroup Condition=" '$(TargetFramework)' == 'net6.0' ">
     <PackageReference Include="System.Threading.Tasks.Extensions" Version="4.5.3" />
     <Reference Include="BrowserStackLocal">
-      <HintPath>..\BrowserStackLocal\bin\$(Configuration)\net7.0\BrowserStackLocal.dll</HintPath>
+      <HintPath>..\BrowserStackLocal\bin\$(Configuration)\net6.0\BrowserStackLocal.dll</HintPath>
     </Reference>
   </ItemGroup>
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 

BrowserStackLocal/BrowserStackLocal/BrowserStackLocal.csproj

@@ -2,7 +2,7 @@
   <PropertyGroup>
     <RootNamespace>BrowserStack</RootNamespace>
     <AssemblyName>BrowserStackLocal</AssemblyName>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <Title>BrowserStackLocal</Title>
     <Product>BrowserStackLocal</Product>

BrowserStackLocal/BrowserStackLocalIntegrationTests/BrowserStackLocalIntegrationTests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net7.0</TargetFrameworks>
+    <TargetFrameworks>net6.0</TargetFrameworks>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
@@ -12,10 +12,10 @@
     <PackageReference Include="Selenium.WebDriver" Version="3.141.0" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'net7.0' ">
+  <ItemGroup Condition=" '$(TargetFramework)' == 'net6.0' ">
     <PackageReference Include="System.Threading.Tasks.Extensions" Version="4.5.3" />
     <Reference Include="BrowserStackLocal">
-      <HintPath>..\BrowserStackLocal\bin\$(Configuration)\net7.0\BrowserStackLocal.dll</HintPath>
+      <HintPath>..\BrowserStackLocal\bin\$(Configuration)\net6.0\BrowserStackLocal.dll</HintPath>
     </Reference>
   </ItemGroup>