chore: remove debian-slim comment linking libatomic1 with arm

[MikeMcC399]

Description

Remove the outdated comment linking the use of libatomic1 to arm from Dockerfile-slim.template.

To avoid unnecessarily generating new images, the generated Dockerfiles are left unchanged. They will be updated with each corresponding new release line update.

Motivation and Context

According to https://github.com/nodejs/node/blob/main/BUILDING.md#official-binary-platforms-and-toolchains

Starting with Node.js 25, official Linux binaries are linked with libatomic and these systems must have the libatomic runtime installed and available at execution time to run the binaries. The package name for the libatomic runtime is typically libatomic or libatomic1 depending on your Linux distribution.

debian and debian-slim Docker images do not pre-install the libatomic1 package.

buildpack-deps (for example buildpack-deps:trixie), which the default node is based on, does include libatomic1 package.

docker-node/Dockerfile-slim.template

Line 13 in 766ca4f

# libatomic1 for arm

comment linking libatomic1 with arm is outdated.

node:26-trixie-slim images fail to build without libatomic1

Testing Details

Confirm that 26/trixie-slim fails to build without libatomic1 on x64.

Types of changes

• Documentation
• Version change (Update, remove or add more Node.js versions)
• Variant change (Update, remove or add more variants, or versions of variants)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Other (none of the above)

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING.md document.
• All new and existing tests passed.