chore(deps): update docker.io/library/postgres docker tag to v18

[renovate]

This PR contains the following updates:

Package	Update	Change
docker.io/library/postgres	major	15.2 → 18.4
docker.io/library/postgres	major	16 → 18
docker.io/library/postgres	major	16-alpine → 18-alpine
docker.io/library/postgres	major	13-alpine → 18-alpine

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