Revert "Merge branch 'zacharysabourin/main/slack-app-use-legacy' into 'main'"

• Revert "Merge branch 'zacharysabourin/main/slack-app-use-legacy' into 'main'"

This reverts merge request !725 (merged)

requested review from @cguindon, @malowe, @epoirier, @zacharysabourin, and @oliviergoulet

assigned to @zacharysabourin

approved this merge request

Switching to "legacy" slash command support was to try and circumvent the 'dispatch_failed' message received from Slack. I thought it was a problem with the app. It turns out it's just because membership staging has auth. The original change didn't need to happen at all

mentioned in commit 222661a6

merged