Build and test conda packages and wheels for Intel Python CI

Adds what Intel Python CI (gh-ci) needs: a ci/ directory and
.github/workflows/intel-ci.yml. The workflow builds conda-recipe/ with
conda-build and the wheels with cibuildwheel, for every platform and Python
version the recipe and pyproject.toml declare, and tests each package in a
clean environment with ci/test.py. Intel's Jenkins tests them again, scans
them, runs ci/benchmark.py on the newest Linux package, and publishes a
release tag's tested packages as its GitHub Release.

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. conda-package-cf.yml
reports the same check names. conda_build_config.yaml now lists the Python
versions, and numpy: '2', as conda-build otherwise defaults to 1.26.

The wheels' run-time requirement on mkl comes from [tool.gh-ci] wheel-requires
in pyproject.toml, which ci/build.py adds to each wheel: in [project] it would
fail the recipe's pip check, as conda-forge's mkl has no pip metadata.

Author: jharlow-intel

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

@@ -84,7 +84,7 @@ jobs:
             "${TEST[@]}" \
             "${VERSIONS[@]}" \
             "${CHANNELS[@]}" \
-            conda-recipe-cf
+            conda-recipe
 
       - name: Upload artifact
         uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2
@@ -165,7 +165,7 @@ jobs:
           conda list -n base
 
       - name: Build conda package
-        run: conda build --no-test --python "${{ matrix.python_spec || matrix.python }}" --numpy ${{ matrix.numpy }} -c conda-forge --override-channels conda-recipe-cf
+        run: conda build --no-test --python "${{ matrix.python_spec || matrix.python }}" --numpy ${{ matrix.numpy }} -c conda-forge --override-channels conda-recipe
 
       - name: Upload artifact
         uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2
@@ -442,7 +442,7 @@ jobs:
             "${TEST[@]}" \
             "${VERSIONS[@]}" \
             "${CHANNELS[@]}" \
-            conda-recipe-cf
+            conda-recipe
 
       - name: Upload artifact
         uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2