Skip MPI clean install via APT on ubuntu

Signed-off-by: sfc-gh-mvashishtha <mahesh.vashishtha@snowflake.com>

.github/workflows/ci.yml

@@ -115,15 +115,15 @@ jobs:
         run: |
           MODIN_ENGINE=dask python -c "import modin.pandas as pd; print(pd.DataFrame([1,2,3]))"
           MODIN_ENGINE=ray python -c "import modin.pandas as pd; print(pd.DataFrame([1,2,3]))"
-      - name: Ensure MPI engine start up
-        # Install a working MPI implementation beforehand so mpi4py can link to it.
-        # Pin libmpich-dev to version 4.0-3. Version 4.2.0-5build3 does not work.
-        # See https://github.com/modin-project/modin/issues/7419.
-        run: |
-          sudo apt install libmpich-dev=4.0-3
-          python -m pip install -e ".[mpi]"
-          MODIN_ENGINE=unidist UNIDIST_BACKEND=mpi mpiexec -n 1 python -c "import modin.pandas as pd; print(pd.DataFrame([1,2,3]))"
-        if: matrix.os == 'ubuntu'
+      # - name: Ensure MPI engine start up
+      # Install a working MPI implementation beforehand so mpi4py can link to it.
+      # TODO(https://github.com/modin-project/modin/issues/7421): Find a
+      # way to make MPI installed via APT work. Then uncomment this section.
+      #   run: |
+      #     sudo apt install libmpich-dev
+      #     python -m pip install -e ".[mpi]"
+      #     MODIN_ENGINE=unidist UNIDIST_BACKEND=mpi mpiexec -n 1 python -c "import modin.pandas as pd; print(pd.DataFrame([1,2,3]))"
+      #   if: matrix.os == 'ubuntu'
 
   test-internals:
     needs: [lint-flake8, python-filter]