Bump debian from buster-20210721 to buster-20231009 in /docker/validator

Bumps debian from buster-20210721 to buster-20231009.

---
updated-dependencies:
- dependency-name: debian
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

docker/validator/Dockerfile

@@ -1,4 +1,4 @@
-FROM debian:buster-20210721@sha256:cc58a29c333ee594f7624d968123429b26916face46169304f07580644dde6b2 AS toolchain
+FROM debian:buster-20231009@sha256:853b9ec779e55f670cbdcb5e15bfb778b5be2c5c61fc8c655638b7a977d273c6 AS toolchain
 
 # To use http/https proxy while building, use:
 # docker build --build-arg https_proxy=http://fwdproxy:8080 --build-arg http_proxy=http://fwdproxy:8080
@@ -20,7 +20,7 @@ COPY . /diem
 RUN IMAGE_TARGETS="release" ./docker/build-common.sh
 
 ### Production Image ###
-FROM debian:buster-20210721@sha256:cc58a29c333ee594f7624d968123429b26916face46169304f07580644dde6b2 AS prod
+FROM debian:buster-20231009@sha256:853b9ec779e55f670cbdcb5e15bfb778b5be2c5c61fc8c655638b7a977d273c6 AS prod
 
 RUN apt-get update && apt-get install -y libssl1.1 && apt-get clean && rm -r /var/lib/apt/lists/*