Update Emscripten binary wheels to include Emscripten platform tags. More work split off from #2591.

### Checklists

- [x] Add a [CHANGELOG](https://github.com/pyodide/pyodide/blob/main/docs/project/changelog.md) entry


from pyodide_test_runner import run_in_pyodide


@run_in_pyodide(packages=["xarray"])
def test_xarray():
    import xarray as xr

    da = xr.DataArray(data=[[0, 1, 2], [3, 4, 5]], dims=("x", "y"))
    xr.testing.assert_equal(a=da.mean(), b=xr.DataArray(data=2.5))

from pyodide_test_runner import run_in_pyodide


@run_in_pyodide(packages=["xarray"])
def test_xarray():
    import xarray as xr

    da = xr.DataArray(data=[[0, 1, 2], [3, 4, 5]], dims=("x", "y"))
    xr.testing.assert_equal(a=da.mean(), b=xr.DataArray(data=2.5))
