chore: Replace serde_yaml with yaml_serde

[xeniape]

Description

Part of stackabletech/issues#898

Integrationtests

--- PASS: kuttl (69.60s)
    --- PASS: kuttl/harness (0.00s)
        --- PASS: kuttl/harness/overrides (6.48s)
        --- PASS: kuttl/harness/custom-lbclass_openshift-false_loadbalancer-allocatenodeports-true (7.54s)
        --- PASS: kuttl/harness/smoke-nodeport_openshift-false_addressType-IP (31.03s)
        --- PASS: kuttl/harness/smoke-nodeport_openshift-false_addressType-Hostname (45.48s)
        --- PASS: kuttl/harness/custom-lbclass_openshift-false_loadbalancer-allocatenodeports-false (7.43s)
        --- PASS: kuttl/harness/smoke-nodeport_openshift-false_addressType-HostnameConservative (24.09s)
PASS

Unittests

test result: ok. 11 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
test result: ok. 5 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s

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