[JENKINS-56870] Disable randomly failing install tests

[jsoref]

See JENKINS-56870.

Proposed changelog entries

Submitter checklist

• JIRA issue is well described
• Changelog entry appropriate for the audience affected by the change (users or developer, depending on the change). Examples
  * Use the Internal: prefix if the change has no user-visible impact (API, test frameworks, etc.)
• Appropriate autotests or explanation to why this change has no tests
• For dependency updates: links to external changelogs and, if possible, full diffs

Desired reviewers

@MuSigma @daniel-beck

[jsoref]

Sigh, #3962 apparently fixed this better