[toolchain] how to point the local toolchan in the bazel rule？

### Description

i dont want to use remote prebuild toolchain,how to change bazel scripit。

Start by locating the Bazel rule that selects the remote prebuilt toolchain and read its toolchain configuration. Determine whether a local toolchain is already supported and document or implement the required selection; done means a local toolchain can be selected successfully instead of the remote one.

Written by the indexing model from the issue text.