Point Whitehall to dedicated RDS instance on Integration
Point Whitehall to dedicated RDS instance on Integration

We're not ready to apply this to all environment yet, so can't make the 
changes in the [common.yaml][].

The password for the database users in whitehall are set in the 
[common.yaml](https://github.com/alphagov/govuk-puppet/blob/main/hieradata_aws/common.yaml#590) 
so we don't need them again here.

[common.yaml]: 
https://github.com/alphagov/govuk-puppet/blob/fdf2678eab4f498f1daa0bc3e765996c6002d665/hieradata_aws/common.yaml#L595-L597

Trello: 
https://trello.com/c/OnPpEYlk/59-run-integration-applications-on-postgres-13-and-mysql-8

alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet