[CI] Fix the runner's memory check

[mwu-tow]

Pull Request Description

The sysinfo crate returns now bytes, not kilobytes.

This was changed in sysinfo's 0.26.0 version. I have missed this change previously while bumping CI code dependencies.

The effects were not drastic as both fast and slow paths were meant to be generally equivalent.

Important Notes

Checklist

Please ensure that the following checklist has been satisfied before submitting the PR:

• The documentation has been updated, if necessary.
• Screenshots/screencasts have been attached, if there are any visual changes. For interactive or animated visual changes, a screencast is preferred.
• All code follows the
  Scala,
  Java,
  and
  Rust
  style guides. In case you are using a language not listed above, follow the Rust style guide.
• All code has been tested:
  • Unit tests have been written where possible.
  • If GUI codebase was changed, the GUI was tested when built using ./run ide build.

[Akirathan]

buildEngineDistribution is a command required for many other commands (for example, dry-run benchmarks and Enso tests). I believe that, at least on Linux, this command is usually run as the very first command. We should ensure that this is run also on other architectures. If not, we may bump into weird dependency issues. Please ensure that self.config.build_engine_package is set on MacOS and Windows as well.

[hubertp]

Looks alright