chore: Rescue slack link unfurling errors. (#11033)

Fixes
https://linear.app/chatwoot/issue/CW-4122/slackwebapierrorsmissingscope-missing-scope

This PR adds the ability to handle errors when scopes are missing during
link unfurling. Since link unfurling is just a nice-to-have feature that
doesn't affect core functionality, we will silently ignore these errors.

---------

Co-authored-by: Sojan <sojan@pepalo.com>

lib/integrations/slack/send_on_slack_service.rb

@@ -18,6 +18,10 @@ class Integrations::Slack::SendOnSlackService < Base::SendOnChannelService
     slack_client.chat_unfurl(
       event
     )
+    # You may wonder why we're not requesting reauthorization and disabling hooks when scope errors occur.
+    # Since link unfurling is just a nice-to-have feature that doesn't affect core functionality, we will silently ignore these errors.
+  rescue Slack::Web::Api::Errors::MissingScope => e
+    Rails.logger.warn "Slack: Missing scope error: #{e.message}"
   end
 
   private