Avoid having to update PreReleaseBrandingLabel for each release (#63799)

* Initial plan

* Implement automatic calculation of PreReleaseBrandingLabel

Co-authored-by: mmitche <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: mmitche <[email protected]>

Author: Copilot

docs/UpdatingMajorVersionAndTFM.md

@@ -14,7 +14,7 @@ Typically, we will update the Major Version before updating the TFM. This is bec
   1. Increment `AspNetCoreMajorVersion` by 1.
   2. Change `PreReleaseVersionIteration` to `1`.
   3. Change `PreReleaseVersionLabel` to `alpha`.
-  4. Change `PreReleaseBrandingLabel` to `Alpha $(PreReleaseVersionIteration)`.
+  Note: `PreReleaseBrandingLabel` is automatically calculated based on `PreReleaseVersionLabel` and does not need to be manually updated.
 * Add entries to [NuGet.config](/NuGet.config) for the new Major Version's feed. This just means copying the current feeds (e.g. `dotnet8` and `dotnet8-transport`) and adding entries for the new feeds (`dotnet9` and `dotnet9-transport`). Make an effort to remove old feeds here at the same time.
 * In [src/ProjectTemplates/Shared/TemplatePackageInstaller.cs](/src/ProjectTemplates/Shared/TemplatePackageInstaller.cs), add an entry to `_templatePackages` for `Microsoft.DotNet.Web.ProjectTemplates` matching the new version.
 * In [eng/targets/CSharp.Common.props](/eng/targets/CSharp.Common.props) for the previous release branch, modify the `<LangVersion>` to be a hardcoded version instead of `preview`. (e.g. If main is being updated to 8.0.0 modify the `<LangVersion>` in the release/7.0 branch). See https://learn.microsoft.com/dotnet/csharp/language-reference/configure-language-version#defaults to find what language version to use.

eng/Versions.props

@@ -20,7 +20,12 @@
     <StabilizePackageVersion Condition="'$(StabilizePackageVersion)' == ''">false</StabilizePackageVersion>
     <DotNetFinalVersionKind Condition="'$(StabilizePackageVersion)' == 'true'">release</DotNetFinalVersionKind>
     <PreReleaseVersionLabel>rc</PreReleaseVersionLabel>
-    <PreReleaseBrandingLabel>RC $(PreReleaseVersionIteration)</PreReleaseBrandingLabel>
+    <!-- PreReleaseBrandingLabel is automatically calculated based on PreReleaseVersionLabel -->
+    <PreReleaseBrandingLabel Condition="'$(PreReleaseVersionLabel)' == 'alpha'">Alpha $(PreReleaseVersionIteration)</PreReleaseBrandingLabel>
+    <PreReleaseBrandingLabel Condition="'$(PreReleaseVersionLabel)' == 'preview'">Preview $(PreReleaseVersionIteration)</PreReleaseBrandingLabel>
+    <PreReleaseBrandingLabel Condition="'$(PreReleaseVersionLabel)' == 'rc'">RC $(PreReleaseVersionIteration)</PreReleaseBrandingLabel>
+    <PreReleaseBrandingLabel Condition="'$(PreReleaseVersionLabel)' == 'rtm'">RTM</PreReleaseBrandingLabel>
+    <PreReleaseBrandingLabel Condition="'$(PreReleaseVersionLabel)' == 'servicing'">Servicing</PreReleaseBrandingLabel>
     <IncludePreReleaseLabelInPackageVersion>true</IncludePreReleaseLabelInPackageVersion>
     <IncludePreReleaseLabelInPackageVersion Condition=" '$(DotNetFinalVersionKind)' == 'release' ">false</IncludePreReleaseLabelInPackageVersion>
     <AspNetCoreMajorMinorVersion>$(AspNetCoreMajorVersion).$(AspNetCoreMinorVersion)</AspNetCoreMajorMinorVersion>