Fix CI

.github/workflows/ci.yml

@@ -25,14 +25,15 @@ jobs:
             docker_image: graphcore/poplar:3.2.0-ubuntu-20.04-20230314
             build_docs: false
     steps:
-      - name: "Install g++ and git"
-        # g++ is needed to build the wrapper, git to publish the docs.
+      - name: "Install, g++, git, jq"
+        # g++ is needed to build the wrapper, git to publish the docs, jq for
+        # the `julia-actions/cache` workflow
         run: |
           apt-get update -y
-          apt-get install -y g++ git
+          apt-get install -y g++ git jq
         env:
           DEBIAN_FRONTEND: noninteractive
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: "Declare git repo safe"
         # In the docker container the repo is owned by 1001:123, causing the
         # following error when running git commands: