Fix Dockerfile - do not download R component

[Akirathan]

Pull Request Description

The latest nightly release action is failing in https://github.com/enso-org/enso/actions/runs/5640089073/job/15281429023#step:10:542 when building the Docker image. It is because gu no longer provides R component. This PR just removes the component and therefore fixes the nightly release actions.

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.