Update CMake version to 3.31 in Dockerfile

Author: scotthart

ci/cloudbuild/dockerfiles/demo-debian-bullseye.Dockerfile

@@ -27,7 +27,7 @@ RUN apt-get update && \
         libssl-dev m4 make ninja-build pkg-config tar wget zlib1g-dev libc6-dbg
 # ```
 
-# #### Install CMake v3.22
+# #### Install CMake v3.31
 WORKDIR /var/tmp/build/cmake
 RUN curl -fsSL https://github.com/Kitware/cmake/archive/v3.31.12.tar.gz | \
     tar -xzf - --strip-components=1 && \