fix: bump rocm-docs-core pin to 1.40.2

[pmoutsias-amd]

Motivation

env/sphinx/requirements.in on this branch still pinned rocm-docs-core to 1.40.1. Downstream consumers of the legacy raw-URL lockfile mechanism (e.g. ROCm/legacy-rocm-build's docs/10.0.0 branch, via -r https://raw.githubusercontent.com/ROCm/rocm-docs-core/new_data/env/sphinx/requirements.txt) were therefore stuck on 1.40.1 instead of picking up the latest 1.40.2 release.

Technical Details

• Bumped rocm-docs-core[api_reference,llms]==1.40.1 → ==1.40.2 in requirements.in.
• Regenerated requirements.txt with pip-compile using Python 3.10 (matching the original lockfile's declared interpreter) to keep the diff limited to the version bump.

Test Plan

• Diffed the regenerated lockfile against the original to confirm only the rocm-docs-core pin and the pip-compile command comment changed.

Test Result

• requirements.txt now pins rocm-docs-core[api-reference,llms]==1.40.2, no unrelated dependency drift.

Submission Checklist

• Look over the contributing guidelines at https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.