chore: update CozyStack upstream to v1.6.2

[kingdonb]

🤖 Automated CozyStack Dependency Update

This PR updates our CozyStack upstream release pin.

Changes:

• Release: v1.6.2
• Released: 2026-08-19T07:52:16Z
• Patch compatibility: failure

Changes in v1.6.2 (since v1.6.1)

bfde94f chore(release): promote v1.6.2-rc.1 -> v1.6.2 (#3904)
00dd949 Pin promoted packages artifact for v1.6.2
269d339 Prepare release v1.6.2 (promoted from v1.6.2-rc.1)
fc592ef fix(release): compare host-less image refs on digest alone (#3905)
2cb8c74 test(release): cover the split-map and repository-less ref shapes
4fcc111 fix(release): compare host-less image refs on digest alone
19e158f Prepare release v1.6.2-rc.1
eb11104 [Backport release-1.6] fix(backupstrategy-controller): repair lookup-gated backup objects (#3731)
c572470 [Backport release-1.6] fix(kube-ovn): reload kubeovn-webhook serving certificate on cert-manager renewal (#3730)
ea4bb83 [Backport release-1.6] fix(velero): apply CRD updates on upgrade via CreateReplace (#3728)
5f87265 [Backport release-1.6] fix(backups): request S3 checksum only when required for barman-cloud (non-AWS S3 / Ceph RGW) (#3767)
8358a9b [Backport release-1.6] fix(flux-shard-operator): repair sharded helm-controller crashloop behind an HTTP proxy (#3818)
40a8fde [Backport release-1.6] fix(api): declare OpenAPIModelName for core and sdn types (#3812)
f6f1861 ci(release): complete the candidate-aware promotion pipeline on release-1.6 (#3893)
672a32b test(release): pin the promotion contract this branch has to satisfy
5673249 ci(release): validate the tag-time changelog and port it from the tag
7df3501 ci(release): run the full e2e suite on rc tag pushes from release-1.6
e85482b ci(release): complete the candidate-aware promotion pipeline on release-1.6
2107d80 docs(flux-shard-operator): drop unproven mechanism from proxy comments
daf4409 test(flux-shard-operator): assert full startupProbe contract and reject alias regression

⚠️ Potential Breaking Changes Detected:

672a32b test(release): pin the promotion contract this branch has to satisfy

🧪 Pre-flight Checks

• Latest non-prerelease release tag identified
• Patch compatibility tested
  - [ ] ⚠️ Patch conflicts detected - manual review required

🚀 Next Steps

1. Review the upstream changes above
2. Verify CI pipeline passes with new upstream
3. Test ARM64 build with new CozyStack version
4. Merge when ready

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This PR was automatically created by the dependency update workflow