Bump rocm-docs-core[api_reference] from 1.20.1 to 1.21.0 in /docs/sphinx (#160)

Bumps [rocm-docs-core[api_reference]](https://github.com/ROCm/rocm-docs-core) from 1.20.1 to 1.21.0.
- [Release notes](https://github.com/ROCm/rocm-docs-core/releases)
- [Changelog](https://github.com/ROCm/rocm-docs-core/blob/develop/CHANGELOG.md)
- [Commits](https://github.com/ROCm/rocm-docs-core/compare/v1.20.1...v1.21.0)

---
updated-dependencies:
- dependency-name: rocm-docs-core[api_reference]
  dependency-version: 1.21.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

docs/sphinx/requirements.in

@@ -1 +1 @@
-rocm-docs-core[api_reference]==1.20.1
+rocm-docs-core[api_reference]==1.21.0

docs/sphinx/requirements.txt

@@ -161,7 +161,6 @@ packaging==24.1
     # via
     #   ipykernel
     #   matplotlib
-    #   pydata-sphinx-theme
     #   sphinx
 parso==0.8.4
     # via jedi
@@ -181,7 +180,7 @@ pure-eval==0.2.3
     # via stack-data
 pycparser==2.22
     # via cffi
-pydata-sphinx-theme==0.15.4
+pydata-sphinx-theme==0.16.1
     # via
     #   rocm-docs-core
     #   sphinx-book-theme
@@ -227,7 +226,7 @@ requests==2.32.3
     # via
     #   pygithub
     #   sphinx
-rocm-docs-core[api-reference]==1.20.1
+rocm-docs-core[api-reference]==1.21.0
     # via -r requirements.in
 rpds-py==0.22.3
     # via