Release: Slack CLI v4.8.0

Version 4.8.0 of the Slack CLI is here!

• The CLI falls back to manifest.json when the get-manifest hook is unavailable.
• We've added the slack manifest sync command to sync the app manifest between project and app settings.
• We've added a --manifest-source flag to the run and deploy commands.
• We've added support for the code_channels app manifest feature.
• We fixed an issue where interactive selection prompts left lingering rendered lines on screen after a selection is made.