Changelog: PR 78 should not be included

[Kevsy]

Problem description

Changelog: #78 ("Delete redundant API-Readiness-Checklist file") was administrative, not API consumer relevant.

Expected action

Remove PR #78 ("Delete redundant API-Readiness-Checklist file") from ### Removed in CHANGELOG.md

[hdamker]

@Kevsy that was actually not an issue to be fixed on main but a direct review comment regarding the CHANGELOG in #88. As r3.2 is now already created and published including the line, the issue is obsolete and can't be act on anymore (the release is done and immutable). I propose to close the issue.