Bump Dockerfile to use latest base image (#259)

New base image includes security fixes. This is an ongoing process to
remediate security issues as they are identified.

Author: tabossert

Dockerfile

@@ -1,5 +1,5 @@
 # syntax=docker/dockerfile:experimental
-FROM quay.io/unstructured-io/base-images:rocky9.2-4@sha256:b1063ffbf08c3037ee211620f011dd05bd2da9287c6e6a3473b15c1597724e4b as base
+FROM quay.io/unstructured-io/base-images:rocky9.2-5@sha256:1721c3b0711e4e90587e3b4917f1b616e4603ddf5b4986bfaa68d02d82a13aba as base
 
 # NOTE(crag): NB_USER ARG for mybinder.org compat:
 #             https://mybinder.readthedocs.io/en/latest/tutorials/dockerfile.html