Make it (a tiny bit) easier to run your own collab (#9557)

* Allow creating channels when seeding
* Allow configuring a custom `SEED_PATH`
* Seed the database when creating/migrating it so you don't need a
  separate step for this.

Release Notes:

- N/A

script/bootstrap

@@ -1,18 +1,12 @@
 #!/usr/bin/env bash
 
-echo "installing foreman..."
-which foreman > /dev/null || brew install foreman
-
-echo "creating database..."
-script/sqlx database create
-
-echo "migrating database..."
-cargo run -p collab -- migrate
-
-echo "seeding database..."
-script/seed-db
-
 if [[ "$OSTYPE" == "linux-gnu"* ]]; then
   echo "Linux dependencies..."
   script/linux
+else
+  echo "installing foreman..."
+  which foreman > /dev/null || brew install foreman
 fi
+
+echo "creating database..."
+script/sqlx database create