Remove the outdated info about inactive clients removal after 180 days

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Description

It removes the wrong info about removal of inactive systems after 180 days

Target branches

• Which product version this PR applies to (Uyuni, SUMA 4.3, SUMA 5.0).

Backport targets (edit as needed):

• master
• 4.3 https://github.com/uyuni-project/uyuni-docs/pull/2994

Links

• This PR tracks issue #<insert spacewalk issue, if any>
• Related development PR #<insert PR link, if any>