feat: add linux-arm64 build and document ARM variants in release notes (#2060)

* Initial plan

* Add linux-arm64 build to CI workflow

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

* Add linux-arm to release notes

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

---------

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

Author: Copilot

azure-pipelines.yml

@@ -116,6 +116,11 @@ stages:
               buildArgs: "-r linux-arm --self-contained -p:PublishSingleFile=true"
               vmImage: ubuntu-22.04
               runTests: ${{ false }}
+            linux-arm64:
+              platformName: linux-arm64
+              buildArgs: "-r linux-arm64 --self-contained -p:PublishSingleFile=true"
+              vmImage: ubuntu-22.04
+              runTests: ${{ false }}
         steps:
           - task: UseDotNet@2
             displayName: Install .NET Core SDK v$(netcoresdk_version)
@@ -1139,6 +1144,8 @@ stages:
                 [Rnwood.Smtp4dev.Desktop-win-x64-$(tag).zip](../../releases/download/$(tag)/Rnwood.Smtp4dev.Desktop-win-x64-$(tag).zip) | Windows x64 binary standalone - Desktop app edition.
                 [Rnwood.Smtp4dev-win-arm64-$(tag).zip](../../releases/download/$(tag)/Rnwood.Smtp4dev-win-arm64-$(tag).zip) | Windows ARM 64-bit binary standalone
                 [Rnwood.Smtp4dev-linux-x64-$(tag).zip](../../releases/download/$(tag)/Rnwood.Smtp4dev-linux-x64-$(tag).zip) | Linux x64 (Intel 64 bit) binary standalone
+                [Rnwood.Smtp4dev-linux-arm64-$(tag).zip](../../releases/download/$(tag)/Rnwood.Smtp4dev-linux-arm64-$(tag).zip) | Linux ARM 64-bit binary standalone
+                [Rnwood.Smtp4dev-linux-arm-$(tag).zip](../../releases/download/$(tag)/Rnwood.Smtp4dev-linux-arm-$(tag).zip) | Linux ARM 32-bit binary standalone
                 [Rnwood.Smtp4dev-linux-musl-x64-$(tag).zip](../../releases/download/$(tag)/Rnwood.Smtp4dev-linux-musl-x64-$(tag).zip) | Linux MUSL x64 binary standalone for Linux distros using MUSL libc
                 [Rnwood.Smtp4dev-noruntime-$(tag).zip](../../releases/download/$(tag)/Rnwood.Smtp4dev-noruntime-$(tag).zip) | Architecture independent version. Should run on any platform where the .NET 8.0 (or greater) runtime is installed
                 [Docker images for Windows and Linux](https://hub.docker.com/layers/rnwood/smtp4dev/$(tag)) - [How to use Docker image](https://github.com/rnwood/smtp4dev/blob/master/docs/Installation.md#how-to-run-smtp4dev-in-docker)