revert: add renovate auto-approve workflow (#80)

Replaced by the Mend renovate-approve GitHub App which handles
Renovate PR approvals natively without needing per-repo workflow files.

Signed-off-by: jimisola <jimisola@jimisola.com>
Co-authored-by: Jimisola Laursen <jimisola.laursen@resurs.se>

Author: jimisola