Add note on enabling minor version of BaseOS and AppStream RPMs

[Levi-Leah]

What changes are you introducing?

Ads a note to enable minor version of BaseOS and AppStream RPMs.

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

Based on the the leapp supported upgrade path we currently need 9.5 minor repositories; upgrade fails otherwise

Bug SAT-29652 (public)

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

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.

[github-actions]

The PR preview for 295d411 is available at theforeman-foreman-documentation-preview-pr-3651.surge.sh

The following output files are affected by this PR:

• Upgrading_Project/index-satellite.html
• Upgrading_Project_Disconnected/index-satellite.html

show diff

show diff as HTML

[evgeni]

We document that people should run subscription-manager release --unset after the upgrade (in the connected case, and capsules are always considered "connected"), if they only have the 9.Y repos synced, this will break for them. So technically you need both repo versions available: "9" and "9.Y".