chore(deps): update dep slack from 4.15.0 to v6

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
slack	orb	major	4.15.0 -> 6.0.0

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), 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.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

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

---

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

[relativeci]

#4325 Bundle Size — 9.39MiB (0%).

1a903bb(current) vs a6ece95 main#4322(baseline)

Warning

Bundle contains 36 duplicate packages – View duplicate packages

Bundle metrics   1 change

	Current #4325	Baseline #4322
Initial JS	3.71MiB	3.71MiB
Initial CSS	0B	0B
Cache Invalidation	38.07%	39.5%
Chunks	102	102
Assets	105	105
Modules	6039	6039
Duplicate Modules	575	575
Duplicate Code	4.29%	4.29%
Packages	303	303
Duplicate Packages	35	35

Bundle size by type  no changes

	Current #4325	Baseline #4322
JS	9.25MiB	9.25MiB
Other	144.53KiB	144.53KiB

Bundle analysis report Branch renovate/slack-6.x Project dashboard

---

^{Generated by RelativeCI Documentation Report issue}