Bump ocaml/setup-ocaml from 2 to 3

Bumps [ocaml/setup-ocaml](https://github.com/ocaml/setup-ocaml) from 2 to 3.
- [Release notes](https://github.com/ocaml/setup-ocaml/releases)
- [Changelog](https://github.com/ocaml/setup-ocaml/blob/master/CHANGELOG.md)
- [Commits](ocaml/setup-ocaml@v2...v3)

---
updated-dependencies:
- dependency-name: ocaml/setup-ocaml
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ jobs:
           sudo apt-get install libsdl2-dev libsdl2-image-dev
 
       - name: Setup OCaml
-        uses: ocaml/setup-ocaml@v2
+        uses: ocaml/setup-ocaml@v3
         with:
           ocaml-compiler: ${{ matrix.ocaml-compiler }}
           opam-repositories: |
@@ -49,10 +49,10 @@ jobs:
         run: git diff --exit-code
 
       - name: Lint opam
-        uses: ocaml/setup-ocaml/lint-opam@v2
+        uses: ocaml/setup-ocaml/lint-opam@v3
 
       - name: Lint fmt
-        uses: ocaml/setup-ocaml/lint-fmt@v2
+        uses: ocaml/setup-ocaml/lint-fmt@v3
 
       - name: Lint doc
-        uses: ocaml/setup-ocaml/lint-doc@v2
+        uses: ocaml/setup-ocaml/lint-doc@v3