chore: Replace serde_yaml with yaml_serde

[razvan]

Description

Part of stackabletech/issues#898

$  ./scripts/run-tests --skip-operator nifi --test-suite smoke-latest
--- PASS: kuttl (729.64s)
    --- PASS: kuttl/harness (0.00s)
        --- PASS: kuttl/harness/smoke_nifi-2.12.0_use-zookeeper-manager-true_zookeeper-latest-3.9.6_openshift-false_listener-class-external-unstable (729.63s)
PASS

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

Author

• Changes are OpenShift compatible
• CRD changes approved
• CRD documentation for all fields, following the style guide.
• Helm chart can be installed and deployed operator works
• Integration tests passed (for non trivial changes)
• Changes need to be "offline" compatible
• Links to generated (nightly) docs added
• Release note snippet added

Reviewer

• Code contains useful comments
• Code contains useful logging statements
• (Integration-)Test cases added
• Documentation added or updated. Follows the style guide.
• Changelog updated
• Cargo.toml only contains references to git tags (not specific commits or branches)

Acceptance

• Feature Tracker has been updated
• Proper release label has been added
• Links to generated (nightly) docs added
• Release note snippet added
• Add type/deprecation label & add to the deprecation schedule
• Add type/experimental label & add to the experimental features tracker

[NickLarsenNZ]

LGTM

[NickLarsenNZ]

LGTM