Bump rocm-docs-core from 0.14.0 to 0.15.0 in /docs/sphinx (#781)

Bumps [rocm-docs-core](https://github.com/RadeonOpenCompute/rocm-docs-core) from 0.14.0 to 0.15.0.
- [Release notes](https://github.com/RadeonOpenCompute/rocm-docs-core/releases)
- [Changelog](https://github.com/RadeonOpenCompute/rocm-docs-core/blob/develop/CHANGELOG.md)
- [Commits](https://github.com/RadeonOpenCompute/rocm-docs-core/compare/v0.14.0...v0.15.0)

---
updated-dependencies:
- dependency-name: rocm-docs-core
  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>

[ROCm/rccl commit: 399d31ed40]

projects/rccl/docs/sphinx/requirements.in

@@ -1 +1 @@
-rocm-docs-core==0.14.0
+rocm-docs-core==0.15.0

projects/rccl/docs/sphinx/requirements.txt

@@ -94,7 +94,7 @@ requests==2.31.0
     # via
     #   pygithub
     #   sphinx
-rocm-docs-core==0.14.0
+rocm-docs-core==0.15.0
     # via -r requirements.in
 smmap==5.0.0
     # via gitdb