[DOC]: cuda.bindings._v2.driver.memcpy missing from driver_v2 API catalog #3381

Problem

The autosummary list in driver_v2.rst names cu_memcpy, but the actual export is cuda.bindings._v2.driver.memcpy. Sphinx reports a failed import and silently drops the entry and its detail page. No broken table row is rendered, so a link-only check will not catch it.

The function exists in the bindings. This is a documentation coverage gap only.

Scope

The v2 driver reference is new relative to 13.4.4, so this gap is new in 13.5.0.

Proposed fix

1. Change cu_memcpy to memcpy in driver_v2.rst.
2. Build the docs and confirm the memcpy catalog row and detail page appear and the import warning is gone.
3. For the already-tagged 13.5.0 docs, ship the correction through the docs-fix process, preserving the release tag.

Context

Found while reviewing the 13.5.0 release dry run for cuda-bindings (#3368).