Add $ to Installation (backport #5356)

[mergify]

---

This is an automatic backport of pull request #5356 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of b3d8114 has failed:

On branch mergify/bp/jazzy/pr-5356
Your branch is up to date with 'origin/jazzy'.

You are currently cherry-picking commit b3d8114.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   source/Installation/Maintaining-a-Source-Checkout.rst
	modified:   source/Installation/RHEL-Install-RPMs.rst
	modified:   source/Installation/Testing.rst
	modified:   source/Installation/Ubuntu-Install-Debs.rst
	modified:   source/Installation/_Apt-Repositories.rst
	modified:   source/Installation/_RHEL-Set-Locale.rst
	modified:   source/Installation/_Ubuntu-Set-Locale.rst

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   source/Installation/Windows-Install-Binary.rst
	both modified:   source/Installation/_Apt-Upgrade-Admonition.rst
	both modified:   source/Installation/_Dnf-Update-Admonition.rst

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[github-actions]

HTML artifacts: https://github.com/ros2/ros2_documentation/actions/runs/14684549320/artifacts/3015266349.

To view the resulting site:

1. Click on the above link to download the artifacts archive
2. Extract it
3. Open html-artifacts-5376/index.html in your favorite browser