[BUG] Initial migration should use IF NOT EXISTS

[jschuur]

The initial migration file generated with drizzle-kit generate for an existing project seemed to use a CREATE TABLE table_name (..) format, rather than
CREATE TABLE IF NOT EXISTS table_name (...).

At least this was the case for me for a turso/sqlite driver/dialect config and drizzle-kit: v0.21.2.

drizzle-kit introspect also did not add IF NOT EXISTS.

Shouldn't IF NOT EXISTS be use here, so that it can gracefully skip existing tables? The same should apply to index generating statements.