Try Setup OCaml v3

Author: dhil

.github/workflows/ci-interpreter.yml

@@ -19,7 +19,7 @@ jobs:
       - name: Checkout repo
         uses: actions/checkout@v2
       - name: Setup OCaml
-        uses: ocaml/setup-ocaml@v2
+        uses: ocaml/setup-ocaml@v3
         with:
           ocaml-compiler: 4.14.x
       - name: Setup OCaml tools