Fix pytest-rerunfailures plugin installation and flaky marker registration

- Register 'flaky' marker in pytest.ini to eliminate warnings about unknown mark
- Fix dependency group references in cuda_core/pyproject.toml to use {include-group = "test"} instead of "cuda-core[test]" extra
- This ensures pytest-rerunfailures is properly installed so @pytest.mark.flaky() decorators work correctly

Example failure fixed by this commit: https://github.com/NVIDIA/cuda-python/actions/runs/22501839950/job/65191834971?pr=1702

Made-with: Cursor

Author: rwgk

cuda_core/pyproject.toml

@@ -57,12 +57,12 @@ cu13 = ["cuda-bindings[all]==13.*"]
 [dependency-groups]
 test = ["cython>=3.2,<3.3", "setuptools", "pytest>=6.2.4", "pytest-randomly", "pytest-repeat", "pytest-rerunfailures"]
 ml-dtypes = ["ml-dtypes>=0.5.4,<0.6.0"]
-test-cu12 = [ {include-group = "ml-dtypes" }, "cuda-core[test]", "cupy-cuda12x; python_version < '3.14'", "cuda-toolkit[cudart]==12.*"]  # runtime headers needed by CuPy
-test-cu13 = [ {include-group = "ml-dtypes" }, "cuda-core[test]", "cupy-cuda13x; python_version < '3.14'", "cuda-toolkit[cudart]==13.*"]  # runtime headers needed by CuPy
+test-cu12 = [ {include-group = "ml-dtypes" }, {include-group = "test" }, "cupy-cuda12x; python_version < '3.14'", "cuda-toolkit[cudart]==12.*"]  # runtime headers needed by CuPy
+test-cu13 = [ {include-group = "ml-dtypes" }, {include-group = "test" }, "cupy-cuda13x; python_version < '3.14'", "cuda-toolkit[cudart]==13.*"]  # runtime headers needed by CuPy
 # free threaded build, cupy doesn't support free-threaded builds yet, so avoid installing it for now
 # TODO: cupy should support free threaded builds
-test-cu12-ft = [ {include-group = "ml-dtypes" }, "cuda-core[test]", "cuda-toolkit[cudart]==12.*"]
-test-cu13-ft = [ {include-group = "ml-dtypes" }, "cuda-core[test]", "cuda-toolkit[cudart]==13.*"]
+test-cu12-ft = [ {include-group = "ml-dtypes" }, {include-group = "test" }, "cuda-toolkit[cudart]==12.*"]
+test-cu13-ft = [ {include-group = "ml-dtypes" }, {include-group = "test" }, "cuda-toolkit[cudart]==13.*"]
 
 [project.urls]
 homepage = "https://nvidia.github.io/cuda-python/"

pytest.ini

@@ -19,3 +19,4 @@ markers =
     core: tests for cuda_core
     cython: cython tests
     smoke: meta-level smoke tests
+    flaky: mark test as flaky (provided by pytest-rerunfailures)