chore: remove releasenotes.yaml (#1111)

<!-- markdownlint-disable MD041 -->
#### What this PR does / why we need it

this action is not really needed since we maintain our release notes
either through the Github Release Notes API directly or via the release
notes file by checking it into the corresponding release branch.

(we didnt use this action in the last 4 releases)

#### Which issue(s) this PR fixes
<!--
Usage: `Fixes #<issue number>`, or `Fixes (paste link of issue)`.
-->