`update-flake-dependencies` job fails if the previous automated PR isn't merged

[mrjones2014]

What does it concern?

The Makefile commands and tooling

Goal or desired behavior

The CI job to update the flake.lock should ideally close the previous PR if it hasn't been merged yet and open a new one.

Current behavior

Currently it just fails because the branch name is already in use (by the previous PR).

Relevant log output

No response

op CLI version

No response

shell-plugins local ref

No response