update ci workflow

Author: zshipko

.github/workflows/test.yml

@@ -19,13 +19,11 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
       - name: Use OCaml ${{ matrix.ocaml-version }}
-        uses: avsm/setup-ocaml@v1
+        uses: ocaml/setup-ocaml@v3
         with:
-          ocaml-version: ${{ matrix.ocaml-version }}
-      - run: opam pin add . --no-action
-      - run: opam depext irmin-watcher --yes --with-doc --with-test
+          ocaml-compiler: ${{ matrix.ocaml-version }}
       - run: opam install . --deps-only --with-doc --with-test
       - run: opam exec -- dune build
       - run: opam exec -- dune runtest