abi3 extension named for build arch on linux-ppc64le cross build

### Solution to issue cannot be found in the documentation.

- [x] I checked the documentation.

### Issue

Summary
-------
On a linux-64 -> linux-ppc64le cross build, setuptools names a
py_limited_api (abi3) extension using the BUILD interpreter's platform
triple. The resulting file cannot be imported by the target interpreter,
so the package test phase fails.

Feedstock: conda-forge/tree-sitter-embedded-template-feedstock PR #6
Reproduced locally with build-locally.py, and on CI.

Expected
--------
_binding.abi3-powerpc64le-linux-gnu.so

Actual
------
_binding.abi3-x86_64-linux-gnu.so (68.35 KiB, correct ppc64le object)
ModuleNotFoundError: No module named
'tree_sitter_embedded_template._binding'

The object itself is correct. It is compiled by
powerpc64le-conda-linux-gnu-cc into build/lib.linux-ppc64le-cpython-315/
and relinked normally. Only the filename carries the wrong triple.
The wheel platform tag is correct: cp310-abi3-linux_ppc64le.

Possibly related: #77

### Installed packages

```shell
│ │ │ _openmp_mutex ┆ 4.5 ┆ 20_gnu ┆ conda-forge ┆ 28.27 KiB │
│ │ │ _python_rc ┆ 1 ┆ ha5edcf3_0 ┆ python_rc ┆ 5.17 KiB │
│ │ │ binutils_impl_linux-64 ┆ 2.46.1 ┆ default_hfdba357_102 ┆ conda-forge ┆ 3.54 MiB │
│ │ │ binutils_impl_linux-ppc64le ┆ 2.46.1 ┆ default_hfc45d48_102 ┆ conda-forge ┆ 3.12 MiB │
│ │ │ binutils_linux-ppc64le ┆ 2.46.1 ┆ default_h492aadc_102 ┆ conda-forge ┆ 35.51 KiB │
│ │ │ bzip2 ┆ 1.0.8 ┆ hda65f42_10 ┆ conda-forge ┆ 251.77 KiB │
│ │ │ ca-certificates ┆ 2026.7.22 ┆ hbd8a1cb_0 ┆ conda-forge ┆ 128.69 KiB │
│ │ │ cross-python_linux-ppc64le ┆ 3.15 ┆ 56_cp315 ┆ conda-forge ┆ 14.05 KiB │
│ │ │ crossenv ┆ 1.5.0 ┆ pyhcf101f3_3 ┆ conda-forge ┆ 34.01 KiB │
│ │ │ gcc_impl_linux-64 ┆ 15.3.0 ┆ h6f13dc8_4 ┆ conda-forge ┆ 79.01 MiB │
│ │ │ gcc_impl_linux-ppc64le ┆ 15.3.0 ┆ h2e14ead_4 ┆ conda-forge ┆ 76.32 MiB │
│ │ │ gcc_linux-ppc64le ┆ 15.3.0 ┆ h8225832_1 ┆ conda-forge ┆ 29.09 KiB │
│ │ │ gxx_impl_linux-ppc64le ┆ 15.3.0 ┆ he48c67a_4 ┆ conda-forge ┆ 13.83 MiB │
│ │ │ icu ┆ 78.3 ┆ py310h44b86e0_2 ┆ conda-forge ┆ 13.79 MiB │
│ │ │ kernel-headers_linux-64 ┆ 6.12.0 ┆ he073ed8_6 ┆ conda-forge ┆ 1.47 MiB │
│ │ │ kernel-headers_linux-ppc64le ┆ 3.10.0 ┆ h3602f99_18 ┆ conda-forge ┆ 908.96 KiB │
│ │ │ ld_impl_linux-64 ┆ 2.46.1 ┆ default_hbd61a6d_102 ┆ conda-forge ┆ 727.83 KiB │
│ │ │ ld_impl_linux-ppc64le ┆ 2.46.1 ┆ default_h7db0acb_102 ┆ conda-forge ┆ 774.38 KiB │
│ │ │ libexpat ┆ 2.8.1 ┆ hecca717_1 ┆ conda-forge ┆ 76.03 KiB │
│ │ │ libffi ┆ 3.7.0 ┆ h81df57d_1 ┆ conda-forge ┆ 66.41 KiB │
│ │ │ libgcc ┆ 16.2.0 ┆ ha9f2e26_4 ┆ conda-forge ┆ 1.01 MiB │
│ │ │ libgcc-devel_linux-64 ┆ 15.3.0 ┆ h2b852eb_104 ┆ conda-forge ┆ 2.95 MiB │
│ │ │ libgcc-devel_linux-ppc64le ┆ 15.3.0 ┆ h9ac1e5a_4 ┆ conda-forge ┆ 776.50 KiB │
│ │ │ libgomp ┆ 16.2.0 ┆ he0feb66_4 ┆ conda-forge ┆ 624.97 KiB │
│ │ │ libiconv ┆ 1.18 ┆ h0cb94f2_3 ┆ conda-forge ┆ 770.97 KiB │
│ │ │ liblzma ┆ 5.8.3 ┆ hb03c661_1 ┆ conda-forge ┆ 110.35 KiB │
│ │ │ libmpdec ┆ 4.0.0 ┆ hb03c661_2 ┆ conda-forge ┆ 90.58 KiB │
│ │ │ libsanitizer ┆ 15.3.0 ┆ h54950a5_4 ┆ conda-forge ┆ 7.23 MiB │
│ │ │ libsqlite ┆ 3.53.4 ┆ h13e7031_1 ┆ conda-forge ┆ 951.51 KiB │
│ │ │ libstdcxx ┆ 16.2.0 ┆ h934c35e_4 ┆ conda-forge ┆ 6.31 MiB │
│ │ │ libstdcxx-devel_linux-64 ┆ 15.3.0 ┆ hb2c5482_104 ┆ conda-forge ┆ 19.71 MiB │
│ │ │ libstdcxx-devel_linux-ppc64le ┆ 15.3.0 ┆ hea43558_4 ┆ conda-forge ┆ 18.16 MiB │
│ │ │ libuuid ┆ 2.42.3 ┆ hcfc3c73_0 ┆ conda-forge ┆ 39.06 KiB │
│ │ │ libzlib ┆ 1.3.2 ┆ h25fd6f3_3 ┆ conda-forge ┆ 62.22 KiB │
│ │ │ lz4-c ┆ 1.10.0 ┆ hee9eb32_2 ┆ conda-forge ┆ 177.55 KiB │
│ │ │ ncurses ┆ 6.6 ┆ hdb14827_1 ┆ conda-forge ┆ 889.84 KiB │
│ │ │ openssl ┆ 3.6.4 ┆ h781a0a9_0 ┆ conda-forge ┆ 3.05 MiB │
│ │ │ popt ┆ 1.19 ┆ hcfc3c73_2 ┆ conda-forge ┆ 74.18 KiB │
│ │ │ python ┆ 3.15.0rc2 ┆ hcd007b5_101_cp315 ┆ conda-forge ┆ 31.36 MiB │
│ │ │ python_abi ┆ 3.15 ┆ 9_cp315 ┆ conda-forge ┆ 6.64 KiB │
│ │ │ readline ┆ 8.3 ┆ hd6e31c0_1 ┆ conda-forge ┆ 340.72 KiB │
│ │ │ rsync ┆ 3.4.4 ┆ hffd6c76_1 ┆ conda-forge ┆ 369.48 KiB │
│ │ │ sed ┆ 4.10 ┆ h19d0853_0 ┆ conda-forge ┆ 262.19 KiB │
│ │ │ sysroot_linux-64 ┆ 2.39 ┆ hc4b9eeb_6 ┆ conda-forge ┆ 40.10 MiB │
│ │ │ sysroot_linux-ppc64le ┆ 2.17 ┆ hb9c6658_18 ┆ conda-forge ┆ 15.14 MiB │
```

### Environment info

```shell
Environment
-----------
rattler-build 0.75.0
build_platform linux-64
target_platform linux-ppc64le
python 3.15.0rc2 (conda-forge/label/python_rc)
build interpreter hcd007b5_101_cp315
host interpreter hcd8b8f5_101_cp315
cross-python_linux-ppc64le 3.15 build 56_cp315
setuptools 84.0.0
extension built with -DPy_LIMITED_API=0x030A0000
```