Fix GitHub actions CI, retire CircleCI

.github/workflows/docker.yml

@@ -4,15 +4,15 @@ on:
   [pull_request]
 
 jobs:
-  buildx:
+  docker-build:
     runs-on: ubuntu-latest
     steps:
       -
         name: Checkout
         uses: actions/checkout@v2
       -
         uses: docker/setup-buildx-action@v1
-        id: buildx
+        id: docker-build
         with:
           install: true
       -

Dockerfile

@@ -4,15 +4,13 @@ FROM ocaml/opam:debian-ocaml-4.14
 RUN sudo apt-get update
 RUN sudo apt-get install -y \
     build-essential \
-    pkg-config=0.29.2-1 \
+    pkg-config \
     git \
-    libffi-dev=3.3-6 \
-    libgmp-dev=2:6.2.1+dfsg-1+deb11u1 \
-    libgmp3-dev=2:6.2.1+dfsg-1+deb11u1 \
-    libprocps-dev=2:3.3.17-5 \
+    libffi-dev \
+    libgmp-dev \
+    libgmp3-dev \
     libssl-dev \
-    m4=1.4.18-5
-
+    m4
 
 # Create a volume we can work in. For initial build, 
 # we'll copy the local context. To update the snarky