update: configs slack channel

[kpchoy]

Submission Checklist

• [ ] The CHANGELOG.md reflects any feature, bug fixes, or known issues made in the source code
• [ ] New unit tests and integration tests have beed added
• [x] Code coverage is more or equal to the previous coverage
• [x] A visual inspection of the Files changed tab was made prior to submitting the pull request ensuring the style guide was followed
• [x] CI pipeline is green
• [ ] Included screenshot if necessary

Description

Update Slack channel config vars

Breakdown

• [Bulleted summary of changes]
• [eg. Updated doc]
• [eg. Added precondition to class]

Validation

• [Bulleted summary of validation steps including local and CI pipeline]
• [eg. Added new test]
• [eg. Manually tested with both app and server]

Additional Notes

[Any additional comments, notes, or information relevant to reviewers.]

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• [x] I acknowledge that all my contributions will be made under the project's license.