Correctly invoke gh run download

[ekohl]

What changes are you introducing?

In 242dde2 I forgot to add $ to the variable, so it was taking it literally. This is something I tried to fix in 313e77e but didn't.

Why are you introducing these changes? (Explanation, links to references, issues, etc.)

Still broken.

Anything else to add? (Considerations, potential downsides, alternative solutions you have explored, etc.)

If this doesn't work it's probably best to revert the changes.

Checklists

• I am okay with my commits getting squashed when you merge this PR.
• I am familiar with the contributing guidelines.

Please cherry-pick my commits into:

• Foreman 3.13/Katello 4.15 (EL9 only)
• Foreman 3.12/Katello 4.14 (Satellite 6.16)
• Foreman 3.11/Katello 4.13 (orcharhino 6.11 on EL8 only; orcharhino 7.0 on EL8+EL9)
• Foreman 3.10/Katello 4.12
• Foreman 3.9/Katello 4.11 (Satellite 6.15; orcharhino 6.8/6.9/6.10)
• Foreman 3.8/Katello 4.10
• Foreman 3.7/Katello 4.9 (Satellite 6.14)
• We do not accept PRs for Foreman older than 3.7.

[maximiliankolb]

If this doesn't work it's probably best to revert the changes.

Let's retest 🤞