[libc++] Install Python packaging to resolve LLDB data formatter issues (#95971)

This should fix the failures that started happening after #93712 landed.

Author: ldionne

libcxx/utils/ci/Dockerfile

@@ -92,6 +92,7 @@ RUN sudo apt-get update \
         python3 \
         python3-dev \
         python3-distutils \
+        python3-packaging \
         python3-psutil \
         software-properties-common \
         swig4.0 \