[9.0] Make duplicate deb/rpm packages so we can sign them with the new PMC key

[jkoritzinsky]

Contributes to dotnet/arcade#16047

Make duplicate deb/rpm packages so we can sign them with the new PMC key

Description

PMC has added a new signing key for packages published to repositories for new Linux distributions they will add support for, such as Debian 13 and SLES vNext. Packages pushed to these feeds must be signed with the new key. Existing feeds will maintain the same keys. The .NET signing infrastructure requires us to have separate copies of the package files to have them signed with different keys. This PR introduces separate copies of the DEB and RPM installers to be signed with the new signing keys.

Contributes to dotnet/arcade#16047

Customer Impact

Without this change, we can't ship .deb installers for Debian 13. With this change, we can.

Regression?

• Yes
• No

Risk

• High
• Medium
• Low

[Justify the selection above]

Verification

• Manual (required)
• Automated

Packaging changes reviewed?

• Yes
• No
• N/A

[jkoritzinsky]

/backport to release/8.0

[github-actions]

Started backporting to release/8.0: https://github.com/dotnet/aspnetcore/actions/runs/16951661469

[Copilot]

Pull Request Overview

This PR creates duplicate DEB and RPM package files to support signing with a new PMC (Package Manager Client) key for upcoming Linux distributions like Debian 13 and SLES vNext, while maintaining existing keys for current feeds.

• Introduces new build properties and targets for creating "newkey" variants of installer packages
• Adds copy operations to generate duplicate package files with "-newkey" suffixes
• Maintains existing build processes while extending them to support dual signing requirements

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/Installers/Rpm/Directory.Build.props	Adds NewKeyVersionSuffix property for RPM packages
src/Installers/Rpm/Directory.Build.targets	Implements copy operation to create newkey RPM variants
src/Installers/Rpm/TargetingPack/Rpm.TargetingPack.rpmproj	Defines NewKeyBaseName and NewKeyExtension properties
src/Installers/Rpm/Runtime/Rpm.Runtime.rpmproj	Defines NewKeyBaseName and NewKeyExtension properties
src/Installers/Debian/Directory.Build.targets	Implements copy operation to create newkey DEB variants
src/Installers/Debian/TargetingPack/Debian.TargetingPack.debproj	Defines NewKeyTargetFileName property
src/Installers/Debian/Runtime/Debian.Runtime.debproj	Defines NewKeyTargetFileName property

[Copilot]

The copy operation lacks consistency with the RPM implementation. Consider adding a message task similar to line 114 in the RPM Directory.Build.targets to provide feedback about the copy operation.

Suggested change

	<Copy SourceFiles="$(IntermediateOutputPath)out/$(BuildScriptOutputFileName)" DestinationFiles="$(TargetPath)" />
	<Copy SourceFiles="$(IntermediateOutputPath)out/$(BuildScriptOutputFileName)" DestinationFiles="$(TargetPath)" />
	<Message Text="Copying $(IntermediateOutputPath)out/$(BuildScriptOutputFileName) to $(OutputPath)$(NewKeyTargetFileName)" Importance="high" />

[dotnet-policy-service]

Hi @@jkoritzinsky. This PR was just approved to be included in the upcoming servicing release. Somebody from the @dotnet/aspnet-build team will get it merged when the branches are open. Until then, please make sure all the CI checks pass and the PR is reviewed.