Supabase secrets should be randomised during provisioning

[rl1987]

Supabase 1-click VPS is initialised with the following defaults from docker/.env.example file in Supabase codebase:

############
# Secrets
# YOU MUST CHANGE THESE BEFORE GOING INTO PRODUCTION
############

POSTGRES_PASSWORD=your-super-secret-and-long-postgres-password
JWT_SECRET=your-super-secret-jwt-token-with-at-least-32-characters-long
ANON_KEY=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyAgCiAgICAicm9sZSI6ICJhbm9uIiwKICAgICJpc3MiOiAic3VwYWJhc2UtZGVtbyIsCiAgICAiaWF0IjogMTY0MTc2OTIwMCwKICAgICJleHAiOiAxNzk5NTM1NjAwCn0.dc_X5iR_VP_qT0zsiyj_I_OZ2T9FtRU2BBNWN8Bu4GE
SERVICE_ROLE_KEY=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyAgCiAgICAicm9sZSI6ICJzZXJ2aWNlX3JvbGUiLAogICAgImlzcyI6ICJzdXBhYmFzZS1kZW1vIiwKICAgICJpYXQiOiAxNjQxNzY5MjAwLAogICAgImV4cCI6IDE3OTk1MzU2MDAKfQ.DaYlNEoUrrEn2Ig7tqibS-PHK5vgusbcbo7X36XVt4Q
DASHBOARD_USERNAME=supabase
DASHBOARD_PASSWORD=this_password_is_insecure_and_should_be_updated
SECRET_KEY_BASE=UpNVntn3cDxHJpq99YMc1T1AQgQpc8kfYTuRgBiYa15BLrx8etQoXz3gZv1/u2oq
VAULT_ENC_KEY=your-encryption-key-32-chars-min

This is problematic from security perspective since all Supabase 1-click installs will have the same secrets by default. Some randomisation should be implemented in Packer setup.