Update NativeAOT Docker samples to use .NET 10 images

[Copilot]

Description

Updates Docker sample files in NativeAOT documentation from .NET 8 to .NET 10 images, aligning with the machine images documented in docs/workflow/using-docker.md on the release/10.0 branch.

Changes

• Dockerfile.cross-build-x64-arm64:

  • Buildtools: cbl-mariner-2.0-cross-arm64 → azurelinux-3.0-net10.0-cross-arm64
  • SDK: dotnet/sdk:8.0-cbl-mariner2.0-amd64 → dotnet/sdk:10.0

• Dockerfile.cross-build-x64-x64:

  • Buildtools: cbl-mariner-2.0-cross-amd64 → azurelinux-3.0-net10.0-cross-amd64
  • SDK: dotnet/sdk:8.0-cbl-mariner2.0-amd64 → dotnet/sdk:10.0

• containers.md:

  • Updated oldest compatible Linux version from Ubuntu 16.04 to Ubuntu 18.04 for .NET 10
  • Updated example command to use ubuntu:18.04 instead of ubuntu:16.04
  • Fixed typo where x64-x64 Dockerfile link was pointing to ARM64 version

Original prompt

Create PR to update docker samples in https://github.com/dotnet/runtime/tree/main/src/coreclr/nativeaot/docs to use .NET 10 images.

For buildtools image, use the machine ones from https://github.com/dotnet/runtime/blob/release/10.0/docs/workflow/using-docker.md

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[jkotas]

@copilot Also update https://github.com/dotnet/runtime/blob/main/src/coreclr/nativeaot/docs/containers.md to refer to Ubuntu 18.04 as the oldest compatible version for .NET 10

[Copilot]

@copilot Also update https://github.com/dotnet/runtime/blob/main/src/coreclr/nativeaot/docs/containers.md to refer to Ubuntu 18.04 as the oldest compatible version for .NET 10

Updated in cdccdc0. Changed Ubuntu 16.04 references to Ubuntu 18.04 in both the description and the example command.

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[Copilot]

Pull request overview

This PR updates the NativeAOT Docker sample documentation to use .NET 10 container images, modernizing from the older .NET 8/CBL Mariner 2.0 images to .NET 10/Azure Linux 3.0 images.

Changes:

• Updated base container images from CBL Mariner 2.0 to Azure Linux 3.0 with .NET 10 support
• Updated SDK images from .NET 8 to .NET 10
• Removed the manual symlink creation for the dotnet command (line 3 in both Dockerfiles)
• Corrected Ubuntu compatibility from 16.04 to 18.04 for .NET 10
• Fixed broken hyperlink for x64-x64 Dockerfile

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
Dockerfile.cross-build-x64-x64	Updated from CBL Mariner 2.0/.NET 8 to Azure Linux 3.0/.NET 10 images and removed manual dotnet symlink
Dockerfile.cross-build-x64-arm64	Updated from CBL Mariner 2.0/.NET 8 to Azure Linux 3.0/.NET 10 images and removed manual dotnet symlink
containers.md	Updated Ubuntu compatibility to 18.04, fixed broken Dockerfile link, updated example commands to use ubuntu:18.04

[MichalStrehovsky]

Thank you!