[ci]: Disable wheel testing on ppc64le (#16793)

## Summary

The PPC64le wheel testing job spuriously failes due to some race when
installing python dependencies.
This is very annoying because it requires restarting the release process
over and over again until you're lucky and it passes.

This PR disables wheel testing on PPC64le

This is the same as we did in uv, see
https://github.com/astral-sh/uv/issues/11231

## Test Plan

The wheel test step was skipped in CI, see
3887406516
but it still runs for other targets

.github/workflows/build-binaries.yml

@@ -311,7 +311,7 @@ jobs:
           docker-options: ${{ matrix.platform.maturin_docker_options }}
           args: --release --locked --out dist
       - uses: uraimo/run-on-arch-action@ac33288c3728ca72563c97b8b88dda5a65a84448 # v2
-        if: matrix.platform.arch != 'ppc64'
+        if: ${{ matrix.platform.arch != 'ppc64' && matrix.platform.arch != 'ppc64le'}}
         name: Test wheel
         with:
           arch: ${{ matrix.platform.arch == 'arm' && 'armv6' || matrix.platform.arch }}