Use ocaml/setup-ocaml v3

Author: francoisthire

.github/workflows/build.yml

@@ -22,7 +22,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: setting up opam...
-        uses: ocaml/setup-ocaml@v2
+        uses: ocaml/setup-ocaml@v3
         with:
           ocaml-compiler: ${{ matrix.ocaml-compiler }}
       - name: Install dependencies