Workbench: Remove PDM.

I've had enough for today.

workbench/Dockerfile

@@ -232,8 +232,6 @@ RUN apt-get update && \
     && \
     pipx install chalice && \
     pipx install curator-opensearch && \
-    pipx install 'pdm>=2' && \
-    pipx inject pdm pdm-packer && \
     npm install --global \
         corepack \
         @playwright/test \
@@ -271,7 +269,6 @@ RUN apt-get update && \
     fab --print-completion-script bash > /etc/bash_completion.d/fabric && \
     helm completion bash > /etc/bash_completion.d/helm && \
     semver-bump completion bash > /etc/bash_completion.d/semver-bump && \
-    pdm completion bash > /etc/bash_completion.d/pdm && \
     kompose completion bash > /etc/bash_completion.d/kompose && \
     skaffold completion bash > /etc/bash_completion.d/skaffold && \
     kustomize completion bash > /etc/bash_completion.d/kustomize && \