Install python-dev in the vain hopes of fixing cffi install

Author: anoadragon453

docker/Dockerfile-dhvirtualenv

@@ -33,7 +33,8 @@ RUN env DEBIAN_FRONTEND=noninteractive apt-get install \
         ca-certificates \
         devscripts \
         equivs \
-        wget
+        wget \
+        python3-dev
 
 # fetch and unpack the package
 # We are temporarily using a fork of dh-virtualenv due to an incompatibility with Python 3.11, which ships with