[release-v2.8] Second chart batch release for Rancher v2.8.3

[lucasmlp]

Charts:

elemental 103.1.0+up1.4.2:

• [dev-v2.8] Add Elemental chart v1.4.2 #3491

rancher-backup 103.0.1+up4.0.1:

• Bumping rancher-backups to v4.0.1-rc3 #3299
• Bump backup-restore to 4.0.1-rc4 for dev v2.8.3 #3550
• [dev-v2.8] Un-rc rancher-backup 4.0.1 #3657

rancher-webhook 103.0.2+up0.4.3:

• Bump rancher-webhook to v0.4.3-rc1 #3562
• [v2.8] Bump rancher-webhook to v0.4.3 #3628

system-upgrade-controller 103.0.1+up0.6.0:

• 43730 suc 1.28 #3323

Charts Checklist (built for v5.2.x charts-build-scripts)

Checkpoint 0: Validate release.yaml

Validation steps:

• Each chart version in release.yaml DOES NOT modify an already released chart. If so, stop and modify the versions so that it releases a net-new chart.
• Each chart version in release.yaml IS exactly 1 more patch version than the last released chart version. If not, stop and modify the versions so that it releases a net-new chart.

Checkpoint 1: Compare contents of assets/ to charts/

Validation steps:

• Running make unzip to regenerate the charts/ from scratch, then git diff to check differences between assets/ and charts/ yields NO differences or innocuous differences.

IMPORTANT: Do not undo these changes for future steps since we want to keep the charts/ that match the current contents of assets!

Checkpoint 2: Compare assets against index.yaml

Validation steps:

• The index.yaml file has an entry for each chart version.
• The index.yaml entries for each chart matches the Chart.yaml for each chart.
• Each chart has ALL required annotations
  • kube-version annotation
  • rancher-version annotation
  • permits-os annotation (indicates Windows and/or Linux)

[github-actions]

Validation steps

• Ensure all container images have repository and tag on the same level to ensure that all container images are included in rancher-images.txt which are used by airgap customers.

  Ex:-
    longhorn-controller:
      repository: rancher/hardened-sriov-cni
      tag: v2.6.3-build20230913
  

• Add a 👍 (thumbs up) reaction to this comment once done. CI won't pass without this reaction to the github-action bot's latest validation comment.
• Approve the PR to run the CI check.

[github-actions]

Validation steps

• Ensure all container images have repository and tag on the same level to ensure that all container images are included in rancher-images.txt which are used by airgap customers.

  Ex:-
    longhorn-controller:
      repository: rancher/hardened-sriov-cni
      tag: v2.6.3-build20230913
  

• Add a 👍 (thumbs up) reaction to this comment once done. CI won't pass without this reaction to the github-action bot's latest validation comment.
• Approve the PR to run the CI check.