Fix deploy action

[hrodmn]

There were several problems:

• the sneakiest one was that the CONFIG_YAML environment variable had to be changed from double to single quotes in order for it to write to config.yaml correctly with echo 💡
• had to bootstrap the CDK stack for us-west-2
• updated the runtimes to read PGSTAC_SECRET_ARN instead of setting POSTGRES_* variables at deploy time (tracked here PgbouncerSecret not finished updating when PgStacDatabase construct is ready to use eoapi-cdk#122)

Other fixes:

• switch from npm run cdk (without a cdk script entry) to npx cdk
• ensure consistency of aws-cdk versions across the package