postgres: postgres:17-alpine + securityContext

[mathieu-benoit]

More security for the default postgres in-cluster res pack:

• postgres:17-alpine
• securityContext --> This is required for customers using Pod Security Standard (PSS/PSA) for example.
• automountServiceAccountToken=false

Not related to this, but also took the initiative to change storage: 10Gi to 1Gi instead, 10Gi was excessive according to me.

Tested with with score-k8s: score-spec/score-k8s#38.

https://github.com/score-spec/sample-score-app successfully deployed in Humanitec with this new postgres res pack:

NAME                                          READY   STATUS    RESTARTS        AGE
hello-world-777fd66989-g4jv7                  2/2     Running   1 (4m26s ago)   4m31s
postgres-modules-hello-world-externals-db-0   2/2     Running   0               5m7s

[mathieu-benoit]

Ready for your review, thanks!

[chrishumanitec]

Not tested, but LGTM