Remove apalis + redis => use postgresql instead

crates/steep-server/src/metrics.rs

@@ -54,7 +54,7 @@ pub fn describe() {
     describe_counter!(
         "steep_webhooks_enqueue_failed_total",
         Unit::Count,
-        "Webhooks dropped because enqueueing to Redis failed"
+        "Webhooks dropped because enqueueing to PostgreSQL failed"
     );
     describe_gauge!(
         "steep_bot_tasks_active",