chore(deps): sync postgres digest to constants.py

Dependabot bumped the postgres pin in dependabot-pins.Dockerfile but left
POSTGRES_IMAGE on the old digest. Same version (18.4), rebuilt image.

Signed-off-by: Andrew Chin <achin34@gatech.edu>

Author: azchin

oss_crs/src/constants.py

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # Container images used by the infrastructure sidecar stack.
 LITELLM_IMAGE = "ghcr.io/berriai/litellm-database@sha256:8075b09298dc2453316ebe6152603da34d4b1a0661a3cd756a11191a5b40d59c"  # v1.94.0
-POSTGRES_IMAGE = "postgres@sha256:3a82e1f56c8f0f5616a11103ac3d47e632c3938698946a7ad26da0df1334744a"  # 18.4
+POSTGRES_IMAGE = "postgres@sha256:a02db8cac496f15b094798a38254f14d6e00741f709360e5e00bb6668ea31636"  # 18.4
 
 # Stable local tags for the internal LiteLLM stack images. ``prepare`` pulls
 # each by its immutable digest and applies the local tag; the run template