fix: use correct expression for the release channel

[nirinchev]

Proposed changes

Checklist

• I have signed the MongoDB CLA

[Copilot]

Pull Request Overview

This PR fixes an incorrect reference to determine the release channel in the GitHub Actions workflow for publishing releases. The change corrects a variable reference that was pointing to the wrong source for the release channel information.

• Corrects the release channel reference from steps.npm-tag.outputs.RELEASE_CHANNEL to needs.check.outputs.RELEASE_CHANNEL

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[himanshusinghs]

I see so the problem was the variable we were referring was from a different job hence not available.