ci: add version to built binaries (ocaml#10537)

Signed-off-by: Etienne Millon <[email protected]>

Author: emillon

.github/workflows/binaries.yml

@@ -25,7 +25,10 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0 # for git describe
       - uses: cachix/install-nix-action@v22
+      - run: echo "(version $(git describe --always --dirty --abbrev=7))" >> dune-project
       - run: nix build ${{ matrix.installable }}
       - uses: actions/upload-artifact@v4
         with: