hack/merge_cluster_roles.py: fix deprecation warnings

[pgier]

Newer versions (>= 5.1) of python-yaml (pyyaml) deprecate calling yaml.load() with no Loader argument.
https://msg.pyyaml.org/load
This fixes deprecation warnings in merge_cluster_roles.py and uses the
SafeLoader.

[lilic]

TIL we have this :D Do you mind opening a tech-debt issue to rewrite this in something that is not python, I am fine with bash. Thanks!

/lgtm

[openshift-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: lilic, pgier

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [lilic,pgier]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[openshift-bot]

/retest

Please review the full test history for this PR and help us cut down flakes.

[openshift-bot]

/retest

Please review the full test history for this PR and help us cut down flakes.

[paulfantom]

TIL we have this :D Do you mind opening a tech-debt issue to rewrite this in something that is not python, I am fine with bash.

Personally I don't see why we need to rewrite it to anything. Python is well suited for parsing and outputting yaml (in contrast to bash) and we don't need anything fancy here.

[lilic]

Personally I don't see why we need to rewrite it to anything. Python is well suited for parsing and outputting yaml (in contrast to bash) and we don't need anything fancy here.

Hard to maintain as we are not primarily python developers. Its tech-debt only, and of course team decides if we want to do it? But up to you two, I have not the strongest of feelings around this.

[s-urbaniak]

I think i suggested once to rewrite this in Go, and that suggestion was also rejected. I am also fine with leaving this in Python.

[pgier]

I'd like to open a tech debt issue anyway, since this script is depending on python2 which is now deprecated, and python2 seems to be available in the build/ci container kind of only by chance.