Update bitnami/postgresql Docker tag to v16.3.0

This MR contains the following updates:

Package	Type	Update	Change
bitnami/postgresql	ironbank-docker	minor	16.2.0-debian-12-r8 -> 16.3.0-debian-12-r8
bitnami/postgresql	stage	minor	16.2.0-debian-12-r8 -> 16.3.0-debian-12-r8

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