Clarify support in docs

[bdice]

Clarifies supported platforms on cuML docs homepage.

[bdice]

/merge

[betatim]

Updated this branch to include #6439 which should fix the failing tests

[betatim]

Down to one failure, which looks like something I've seen before, but I don't remember how it got resolved.

FAILED test_random_forest.py::test_rf_classification_seed[small_clf0-float64] - RuntimeError: CUDA error encountered at: file=/opt/conda/conda-bld/work/cpp/src/fil/infer.cu line=903: call='cudaPeekAtLastError()', Reason=cudaErrorContextIsDestroyed:context is destroyed
Obtained 63 stack frames
#1 in /opt/conda/envs/test/lib/python3.10/site-packages/cuml/cluster/../../../../libcuml++.so: raft::cuda_error::cuda_error(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) +0xbd [0x7fc56095331d]
#2 in /opt/conda/envs/test/lib/python3.10/site-packages/cuml/cluster/../../../../libcuml++.so: void ML::fil::infer_k_storage_template<ML::fil::storage<ML::fil::dense_node<double> > >::run<ML::fil::KernelTemplateParams<true, true, (ML::fil::leaf_algo_t)5, 1> >(ML::fil::predict_params) +0x383 [0x7fc560f23ae3]
#3 in /opt/conda/envs/test/lib/python3.10/site-packages/cuml/cluster/../../../../libcuml++.so: void ML::fil::dispatch::dispatch_on_leaf_algo<ML::fil::KernelTemplateParams<true, true, (ML::fil::leaf_algo_t)5, 1>, ML::fil::infer_k_storage_template<ML::fil::storage<ML::fil::dense_node<double> > >, void>(ML::fil::infer_k_storage_template<ML::fil::storage<ML::fil::dense_node<double> > >, ML::fil::predict_params) +0x39e [0x7fc560f4e64e]
#4 in /opt/conda/envs/test/lib/python3.10/site-packages/cuml/cluster/../../../../libcuml++.so: void ML::fil::infer<ML::fil::storage<ML::fil::dense_node<double> > >(ML::fil::storage<ML::fil::dense_node<double> >, ML::fil::predict_params, CUstream_st*) +0xabe [0x7fc560f5477e]

https://github.com/rapidsai/cuml/actions/runs/13921008847/job/38956481959?pr=6452#step:9:3452

[bdice]

That failure is in an optional job, so it's not blocking. I'll go ahead and merge this since it's just a docs update.

[bdice]

/merge