Dockerfile: update debian:bookworm-slim to 39868a6

Closes #14083

Dockerfile

@@ -24,7 +24,7 @@
 #   $ ./maketgz 8.7.1
 
 # To update, get the latest digest e.g. from https://hub.docker.com/_/debian/tags
-FROM debian:bookworm-slim@sha256:84d83b22ba6c367e143fcb7169717d87d7f484356cf9a904f5352418981a99a3
+FROM debian:bookworm-slim@sha256:39868a6f452462b70cf720a8daff250c63e7342970e749059c105bf7c1e8eeaf
 
 RUN apt-get update -qq && apt-get install -qq -y --no-install-recommends \
     build-essential make autoconf automake libtool git perl zip zlib1g-dev gawk && \