Enable Stable Branding .NET 9 GA (#12325)

* Enable Stable Branding .NET 9 GA

* Update Directory.Build.props to disable error NU5104

* Removing extra condition for <WarningsNotAsErrors>

* Update System.Drawing.Common.csproj

* NoWarn NU5104

* NoWarn NU5104 in Microsoft.Private.Winforms

* NoWarn just in System.Drawing.Common

---------

Co-authored-by: Matt Mitchell <[email protected]>
Co-authored-by: Loni Tra <[email protected]>

Author: 3 people

eng/Versions.props

@@ -9,7 +9,7 @@
     <PreReleaseVersionIteration>
     </PreReleaseVersionIteration>
     <VersionPrefix>$(MajorVersion).$(MinorVersion).$(PatchVersion)</VersionPrefix>
-    <StabilizePackageVersion Condition="'$(StabilizePackageVersion)' == ''">false</StabilizePackageVersion>
+    <StabilizePackageVersion Condition="'$(StabilizePackageVersion)' == ''">true</StabilizePackageVersion>
     <DotNetFinalVersionKind Condition="'$(StabilizePackageVersion)' == 'true'">release</DotNetFinalVersionKind>
   </PropertyGroup>
   <!-- Below have corresponding entries in Versions.Details.XML because they are updated via Maestro -->

src/System.Drawing.Common/src/System.Drawing.Common.csproj

@@ -5,7 +5,8 @@
     <!-- Unset TargetFramework as this property gets set in Directory.Build.props. This is necessary to avoid over-building. -->
     <TargetFramework />
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <WarningsNotAsErrors>CS0618</WarningsNotAsErrors>
+    <WarningsNotAsErrors>$(WarningsNotAsErrors);CS0618</WarningsNotAsErrors>
+    <NoWarn>$(NoWarn);NU5104</NoWarn>
     <EnableAOTAnalyzer>false</EnableAOTAnalyzer>
     <Nullable>enable</Nullable>
     <ImplicitUsings>disable</ImplicitUsings>