Remove powerpc64le-unknown-linux-musl target (#9810)

## Summary

This is blocking the release (#9793). We seem to have hit some sort of
limit that's causing builds to fail on this target. It's a Tier 3 Rust
target with _unknown_ (???) `std` support (see the question mark
[here](https://doc.rust-lang.org/rustc/platform-support.html)).

.github/workflows/build-binaries.yml

@@ -578,11 +578,6 @@ jobs:
             maturin_docker_options: -e JEMALLOC_SYS_WITH_LG_PAGE=16
           - target: armv7-unknown-linux-musleabihf
             arch: armv7
-          - target: powerpc64le-unknown-linux-musl
-            arch: ppc64le
-            # see https://github.com/astral-sh/uv/issues/6528
-            maturin_docker_options: -e JEMALLOC_SYS_WITH_LG_PAGE=16
-            toolchain: nightly
       fail-fast: false
 
     steps:
@@ -599,7 +594,7 @@ jobs:
         with:
           target: ${{ matrix.platform.target }}
           manylinux: musllinux_1_1
-          args: ${{ matrix.platform.arch == 'ppc64le' && '--profile release-no-lto' || '--release'}} --locked --out dist --features self-update ${{ matrix.platform.arch == 'aarch64' && '--compatibility 2_17' || ''}}
+          args: --release --locked --out dist --features self-update ${{ matrix.platform.arch == 'aarch64' && '--compatibility 2_17' || ''}}
           docker-options: ${{ matrix.platform.maturin_docker_options }}
           rust-toolchain: ${{ matrix.platform.toolchain || null }}
       - uses: uraimo/run-on-arch-action@v2