DMP-3964 Using postgres v16 in docker

[davet1985]

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JIRA link (if applicable)

https://tools.hmcts.net/jira/browse/DMP-3964

Change description

Using postgres v16 in the local docker build.

When using the new version you might need to remove your docker volume. Stop the postgres image and then use the following commands

docker volume ls
# find darts api db volume
docker volume rm <darts api db volume>

Then you should be able to start the DB using docker once again.

Does this PR introduce a breaking change? (check one with "x")

[ ] Yes
[ ] No