github: remove dependency of python wheel's on dune (#6232)

Ubuntu's dune is way too old for the version generally used. On top of
that the command doesn't fail when this happens, making the setup
brittle. Instead write the version variable to config.mk and run make.

You can see this change running as expected in this run:
https://github.com/xapi-project/xen-api/actions/runs/12792091034/job/35661725368

Author: psafont

.github/workflows/release.yml

@@ -20,13 +20,11 @@ jobs:
           python-version: "3.x"
 
       - name: Install build dependencies
-        run: |
-          pip install build
-          sudo apt-get install ocaml ocaml-dune libfindlib-ocaml-dev libdune-ocaml-dev libcmdliner-ocaml-dev
+        run: pip install build
 
       - name: Generate python package for XenAPI
         run: |
-          ./configure --xapi_version=${{ github.ref_name }}
+          echo "export XAPI_VERSION=${{ github.ref_name }}" > config.mk
           make python
 
       - name: Store python distribution artifacts