Add some missing type libraries for mypy (#9657)

* add some missing types

* install pkg-config

* install pkg-config for docker too

* add pkg-config to plugins

* pkg-config when cryptography may need to be built

* deps cleanup

* more comments

* more tweaks

tools/docker/Dockerfile

@@ -34,6 +34,7 @@ RUN apk add --no-cache --virtual .build-deps \
         python3-dev \
         cargo \
         git \
+        pkgconfig \
     && python tools/pip_install.py --no-cache-dir \
             --editable src/acme \
             --editable src/certbot \