Update slackapi/slack-github-action action to v2

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
slackapi/slack-github-action	action	major	v1.27.1 -> v2.0.0

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Release Notes

slackapi/slack-github-action (slackapi/slack-github-action)

### [`v2.0.0`](https://redirect.github.com/slackapi/slack-github-action/compare/v1.27.1...v2.0.0) [Compare Source](https://redirect.github.com/slackapi/slack-github-action/compare/v1.27.1...v2.0.0)

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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.

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

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[github-actions[bot]]

Code Coverage Report: Only Changed Files listed

Package	Coverage
Overall Coverage	🟢 85%

Minimum allowed coverage is 0%, this run produced 85%