Read sysroot glibc version without conda CLI in build.sh (#3126)

The Linux jobs of the `Conda package` workflow started failing at the
wheel install step (e.g. [this
run](https://github.com/IntelPython/dpnp/actions/runs/40190014878/job/121158805605))
with:

```
ERROR: dpnp-...-3-cp313-cp313-manylinux___x86_64.whl is not a supported wheel on this platform.
```

The `ubuntu-latest` runner image switched from `ubuntu-24.04` to
`ubuntu-26.04`. The new image does not ship Miniconda, so `conda` is no
longer on `PATH`. `conda-recipe/build.sh` used `conda list
'^sysroot_linux-64$'` to get the glibc version for the `manylinux`
platform tag. Under rattler-build that call now fails with `conda:
command not found`, both version parts end up empty, and `wheel tags`
produces the invalid `manylinux___x86_64` tag.

This PR reads the `sysroot_linux-64` version from the `conda-meta`
record in `${BUILD_PREFIX}` instead. The package is a build requirement
(`stdlib('c')`) in both `rattler_recipe.yaml` and `meta.yaml`, so the
record is there under both rattler-build and conda-build. The script now
also fails early with a clear error if the version cannot be detected,
instead of silently producing a broken tag. It also skips the `conda
list` call, which took ~30 seconds per build.

Author: antonwolfy

CHANGELOG.md

@@ -126,6 +126,7 @@ This release is compatible with NumPy 2.5.
 * Fixed importing `dpnp.scipy.sparse` re-enabling the GIL on free-threaded Python builds, because its pybind11 extension did not declare free-threading support [#3101](https://github.com/IntelPython/dpnp/pull/3101)
 * Fixed the CuPy-based `dpnp.scipy` tests under `dpnp/tests/third_party/cupyx/scipy_tests/` missing from the `dpnp` package, so they never ran against an installed package [#3102](https://github.com/IntelPython/dpnp/pull/3102)
 * Fixed a `RuntimeError` raised by kernels of the `blas`, `statistics`, `ufunc` and `window` extensions and of the legacy backend launched over more than `INT_MAX` work-items when built with DPC++ compiler 2026.2 or newer [#3104](https://github.com/IntelPython/dpnp/pull/3104)
+* Fixed the Linux conda build producing a wheel with an invalid `manylinux___x86_64` platform tag when the `conda` CLI is not on `PATH` [#3126](https://github.com/IntelPython/dpnp/pull/3126)
 
 ### Security
 

conda-recipe/build.sh

@@ -12,8 +12,15 @@ export ICPXCFG
 ICXCFG="$(pwd)/icpx_for_conda.cfg"
 export ICXCFG
 
-read -r GLIBC_MAJOR GLIBC_MINOR <<<"$(conda list '^sysroot_linux-64$' \
-    | tail -n 1 | awk '{print $2}' | grep -oP '\d+' | head -n 2 | tr '\n' ' ')"
+# Get sysroot glibc version from the build env metadata (no conda CLI needed)
+SYSROOT_META=("${BUILD_PREFIX}"/conda-meta/sysroot_linux-64-*.json)
+if [[ "${SYSROOT_META[0]##*/}" =~ ^sysroot_linux-64-([0-9]+)\.([0-9]+) ]]; then
+    GLIBC_MAJOR="${BASH_REMATCH[1]}"
+    GLIBC_MINOR="${BASH_REMATCH[2]}"
+else
+    echo "Error: unable to detect sysroot_linux-64 version in ${BUILD_PREFIX}" >&2
+    exit 1
+fi
 
 if [ -e "_skbuild" ]; then
     ${PYTHON} setup.py clean --all