Update all tools

Updates requested from BigBang to match the latest available in BB 1.25.0:

• Flux -> 0.24.0 (will be in BB 1.26.0)
• Istio -> 1.11.3
• Argo -> 2.1.7

Plus latest for:

• Helm -> 3.7.2
• Kubectl -> 1.23.1
• YQ -> 4.16.2
• Sops -> 3.7.1
• SopsSecretGenerator -> 1.4.0
• k9s -> 0.25.18
• Kustomize -> 4.4.1
• Stern -> 1.21.0 (different upstream used)

Removed older (unused) tooling:

• Popeye
• ClusterLint
• Polaris
• Kube-Linter

For #7 (closed)