Build and test conda packages and wheels

Adds a ci/ directory and .github/workflows/intel-ci.yml, which build the
conda packages and the wheels for every declared platform and Python and
test each with ci/test.py on the OpenCL CPU device.

conda-recipe/ is now the only recipe, the conda-forge one that was
conda-recipe-cf/; the Intel-channel recipe and conda-package.yml are
removed. The dev uploads to anaconda.org and their cleanup move into
intel-ci.yml, for pushes to master and tags only. The wheels leave the SYCL
runtime out and require intel-sycl-rt and intel-cmplr-lib-rt, as the PyPI
wheels do; scikit-build is pinned below 1.0 (#2341).

LDFLAGS in the cibuildwheel environment links every Linux library with
-z,relro,-z,now, as conda-forge's compiler activation does for the conda
packages, so libDPCTLSyclInterface.so gets full RELRO like the extensions.
conda-build gets --extra-meta remote_url=... sha=... when GitHub Actions
sets GITHUB_SERVER_URL, GITHUB_REPOSITORY and GITHUB_SHA, so each conda
package records the commit it was built from.

A pull request also builds and tests the newest free-threaded version, and
every push and tag run gets a concurrency group of its own. The benchmarks
take PyYAML from conda-forge, as PyPI has no Python 3.15 wheel for it yet.
ci/build.py refuses two built packages with the same file name, which would
overwrite each other in its flat output directory.

ci/test.py fails when python -m dpctl -f fails, and when the environment's
conda compilers cannot build an extension, instead of deselecting the two
tests that need them. The dev upload takes each wheel's version from its
file name and fails when there is nothing to upload. The benchmarks set
USERPROFILE as well as HOME, and the repair commands match any libsycl
version, as wheel-requires allows any 2026 runtime.

Author: jharlow-intel

.github/workflows/conda-package-cf.yml

@@ -13,7 +13,7 @@ env:
   PACKAGE_NAME: dpctl
   MODULE_NAME: dpctl
   TEST_ENV_NAME: test_dpctl
-  RECIPE_DIR: conda-recipe-cf
+  RECIPE_DIR: conda-recipe
   CHANNELS: "-c conda-forge --override-channels"
   VER_SCRIPT1: "import json; f = open('ver.json', 'r'); j = json.load(f); f.close(); d = j['dpctl'][0];"
   VER_SCRIPT2: "print('='.join((d[s] for s in ('version', 'build'))))"
@@ -60,7 +60,7 @@ jobs:
         with:
           path: ~/.conda/pkgs
           key:
-            ${{ runner.os }}-conda-cf-${{ env.CACHE_NUMBER }}-python-${{ matrix.python }}-spec-${{ matrix.python == '3.14' && contains(matrix.python_spec, 'cp314t') && 't' || '' }}-${{hashFiles('conda-recipe-cf/meta.yaml') }}
+            ${{ runner.os }}-conda-cf-${{ env.CACHE_NUMBER }}-python-${{ matrix.python }}-spec-${{ matrix.python == '3.14' && contains(matrix.python_spec, 'cp314t') && 't' || '' }}-${{hashFiles('conda-recipe/meta.yaml') }}
           restore-keys: |
             ${{ runner.os }}-conda-cf-${{ env.CACHE_NUMBER }}-python-${{ matrix.python }}-spec-${{ matrix.python == '3.14' && contains(matrix.python_spec, 'cp314t') && 't' || '' }}-
             ${{ runner.os }}-conda-cf-${{ env.CACHE_NUMBER }}-
@@ -405,7 +405,7 @@ jobs:
       EXAMPLES_ENV_NAME: examples
       BUILD_ENV_NAME: build_env
       DPCPP_CMPLR: "dpcpp_linux-64>=2026.0"
-      # keep in sync with conda-recipe-cf/conda_build_config.yaml
+      # keep in sync with conda-recipe/conda_build_config.yaml
       GCC_CMPLR_VERSION: '15'
 
     steps: