chore(deps): update github-actions-updates (major)

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
actions/cache	action	major	v4 → v5
actions/checkout	action	major	v5 → v6
actions/download-artifact	action	major	v5 → v7
actions/upload-artifact	action	major	v4 → v6

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Release Notes

actions/cache (actions/cache)

v5

Compare Source

actions/checkout (actions/checkout)

v6

Compare Source

actions/download-artifact (actions/download-artifact)

v7

Compare Source

v6

Compare Source

actions/upload-artifact (actions/upload-artifact)

v6

Compare Source

v5

Compare Source

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Configuration

📅 Schedule: Branch creation - "before 4am on monday" in timezone Europe/Berlin, Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

👻 Immortal: This PR will be recreated if closed unmerged. Get config help if that's undesired.

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• If you want to rebase/retry this PR, check this box

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This PR was generated by Mend Renovate. View the repository job log.

[claude]

Security & Bug Review

I've reviewed this PR and found no security vulnerabilities or bugs in the changes themselves.

Summary

This PR updates GitHub Actions dependencies:

• actions/upload-artifact: v4 → v5
• actions/download-artifact: v5 → v6

Analysis

✅ No Security Issues Found

• These are official GitHub Actions with verified provenance
• Updates are handled by Renovate bot with proper version pinning
• No credential exposure or permission escalation

✅ No Bugs Detected

• All artifact upload/download operations maintain consistent naming (dist, docs, coverage-data-*)
• The merge-multiple: true parameter in download-artifact (line 118 of tests.yml) is compatible with v6
• Artifact retention and path configurations remain unchanged
• Jobs dependencies (needs: tests, needs: release) are unaffected

⚠️ Compatibility Note
The major version bumps suggest potential breaking changes. The most common breaking change in artifact actions is the backend storage format, but this typically doesn't affect workflows using matching upload/download versions. Since both actions are updated together, cross-version compatibility is maintained.

Recommendation: ✅ Safe to merge after CI passes. Monitor the first workflow run to confirm artifact upload/download operations succeed.