Revert "Update Dockerfile_ubuntu_2004_tf_cuda_11 (#539)" (#540)

This reverts commit 4a5fb39.

Author: sganeshb

perfzero/docker/Dockerfile_ubuntu_2004_tf_cuda_11

@@ -6,7 +6,7 @@ FROM nvidia/cuda:11.8.0-cudnn8-devel-ubuntu20.04 as base
 ARG tensorflow_pip_spec="tf-nightly"
 ARG local_tensorflow_pip_spec=""
 ARG extra_pip_specs=""
-ENV PIP_CMD="python3.11 -m pip"
+ENV PIP_CMD="python3.9 -m pip"
 
 # setup.py passes the base path of local .whl file is chosen for the docker image.
 # Otherwise passes an empty existing file from the context.
@@ -40,19 +40,19 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
         lsb-core \
         curl
 
-# Python 3.11 related deps in this ppa.
+# Python 3.9 related deps in this ppa.
 RUN add-apt-repository ppa:deadsnakes/ppa
 
 
 # Install / update Python and Python3
 RUN apt-get install -y --no-install-recommends \
-      python3.11 \
+      python3.9 \
       python3-pip \
-      python3.11-dev \
+      python3.9-dev \
       python3-setuptools \
-      python3.11-venv \
-      python3.11-distutils \
-      python3.11-lib2to3
+      python3.9-venv \
+      python3.9-distutils \
+      python3.9-lib2to3
 
 # Upgrade pip, need to use pip3 and then pip after this or an error
 # is thrown for no main found.