use setup-ocaml@v3

Author: mgree

.github/workflows/build.yml

@@ -80,7 +80,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Use OCaml ${{ matrix.ocaml-compiler }}
-        uses: avsm/setup-ocaml@v2
+        uses: avsm/setup-ocaml@v3
         with:
           ocaml-compiler: ${{ matrix.ocaml-compiler }}
           dune-cache: true