Update instructions in Updating doc

[bangelic]

What changes are you introducing?

Updates the instructions to upgrade 'in-place' for disconnected environments.
Related to closed PR #3770 but only addresses Updating a disconnected {ProjectServer} on {EL} 9

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

https://issues.redhat.com/browse/SAT-24752

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

Contributor 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 3.16/Katello 4.18 (Satellite 6.18)
• Foreman 3.15/Katello 4.17
• Foreman 3.14/Katello 4.16 (Satellite 6.17; orcharhino 7.4)
• Foreman 3.13/Katello 4.15 (EL9 only)
• Foreman 3.12/Katello 4.14 (Satellite 6.16; orcharhino 7.2 on EL9 only; orcharhino 7.3)
• Foreman 3.11/Katello 4.13 (orcharhino 6.11 on EL8 only; orcharhino 7.0 on EL8+EL9; orcharhino 7.1 with Leapp)
• Foreman 3.10/Katello 4.12
• Foreman 3.9/Katello 4.11 (Satellite 6.15; orcharhino 6.8/6.9/6.10)
• We do not accept PRs for Foreman older than 3.9.

[github-actions]

The PR preview for fad4ed5 is available at theforeman-foreman-documentation-preview-pr-4293.surge.sh

The following output files are affected by this PR:

• Updating_Project/index-satellite.html

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show diff as HTML

[Lennonka]

I would like to see a tech review first if you don't mind.