chore!: Remove NiFi 1.x configuration CRD fields

[sbernauer]

Description

Part of stackabletech/docker-images#1498

#944 dropped 1.28.1 from the list of supported version, but we also need to remove all the NiFi 1.x code. This PR does this. Pls note that this removes CRD fields, thus is breaking.
This removes the Prometheus reporting-task Job (and its spec.clusterConfig.createReportingTaskJob field), the pre-2.x non-rolling upgrade handling, the dedicated metrics port, and the sensitive-properties algorithms that were only supported on NiFi 1.x.

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

Release notes

Removed

Dropped support for NiFi 1.x alongside with a few CRD fields that only applied to 1.x and had no effect on NiFi 2.x:

• spec.clusterConfig.createReportingTaskJob (incl. enabled, podOverrides) — NiFi 2.x exposes Prometheus metrics directly at /nifi-api/flow/metrics/prometheus, so the reporting-task Job is obsolete.
• Removed deprecated spec.clusterConfig.sensitiveProperties.algorithm values, please use an supported algorithm instead: nifiArgon2AesGcm256 (default) and nifiPbkdf2AesGcm256

[sbernauer]

Started https://testing.stackable.tech/view/02%20Operator%20Tests%20(custom)/job/nifi-operator-it-custom/99/

[NickLarsenNZ]

I assume this is ok to just remove. I can't think of another way, and the config is no longer supported, so I guess it is fine.

[sbernauer]

I agree. I was also thinking of using CRD versioning, but IIRC we only support renames so far

[NickLarsenNZ]

LGTM