Proj0247: Enable strict mode for package baseline validation

When ensuring backwards compatibility of the API surface of your package, it is advised to do this in strict mode. This helps preventing any unintentional API changes.

More information can be found here, here and here.

Non-compliant

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <EnablePackageValidation>true</EnablePackageValidation>
    <PackageValidationBaselineVersion>1.0.0</PackageValidationBaselineVersion>
    <EnableStrictModeForBaselineValidation>false</EnableStrictModeForBaselineValidation>
  </PropertyGroup>

</Project>

Or:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <EnablePackageValidation>true</EnablePackageValidation>
    <PackageValidationBaselineVersion>1.0.0</PackageValidationBaselineVersion>
  </PropertyGroup>

</Project>

Compliant

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <EnablePackageValidation>true</EnablePackageValidation>
    <PackageValidationBaselineVersion>1.0.0</PackageValidationBaselineVersion>
    <EnableStrictModeForBaselineValidation>true</EnableStrictModeForBaselineValidation>
  </PropertyGroup>

</Project>