Sync omnibus submodule: add external PostgreSQL 17 support

[jashaik]

Summary

Widens external PostgreSQL support in preflight validation from PostgreSQL 14 to PostgreSQL 17, and syncs the omnibus (chef-server-omnibus-config) submodule pointer to include this change.

Changes Made

• In chef-server-omnibus-config (submodule), bumped PostgresqlPreflightValidator::SUPPORTED_VERSION from 14 to 17 in files/server-ctl-cookbooks/infra-server/libraries/preflight_postgres_validator.rb, mirroring the pattern used for the prior PG14 change (commit 458ef0d).
• Updated preflight_postgres_validator_spec.rb boundary tests: version 14.0 now warns (no longer at the max boundary), version 17.0 passes without failure, and versions > 17.x fail with CSPG014.
• Updated the omnibus submodule pointer in this repo to the new commit containing the PG17 change.

The embedded PostgreSQL shipped with Chef Server remains unchanged at 13.x (default['private_chef']['postgresql']['version']); this only widens the range of external PostgreSQL major versions accepted without triggering a CSPG014 preflight failure.

Testing

• Verified the version-comparison logic (major-version match against REQUIRED_VERSION/SUPPORTED_VERSION, warn vs fail boundaries) with a standalone Ruby script covering 9.6, 13.3, 14.0, 17.0, 18.0, and 8.100 — all produced expected outcomes (ok/warn/fail).
• Local rspec run for the submodule spec was blocked by a pre-existing, unrelated macOS bcrypt native-extension code-signing issue in this environment.

This work was completed with AI assistance following Progress AI policies.

[talktovikas]

lgtm