[SYCL][CODEOWNERS] Make intel/llvm-reviewers-runtime design docs codeowners (#9851)

This commit changes the code-owners of the sycl/docs/design section from
@intel/dpcpp-specification-reviewers to intel/llvm-reviewers-runtime.
With this, the intel/llvm-reviewers-runtime would be responsible for
either reviewing the design changes or assign the appropriate teams to
make a design review.

Signed-off-by: Larsen, Steffen <[email protected]>

Author: steffenlarsen

.github/CODEOWNERS

@@ -30,7 +30,7 @@ sycl/ @intel/llvm-reviewers-runtime
 # Documentation
 sycl/ReleaseNotes.md @intel/dpcpp-doc-reviewers @tfzhu
 sycl/doc/ @intel/dpcpp-doc-reviewers
-sycl/doc/design/ @intel/dpcpp-specification-reviewers
+sycl/doc/design/ @intel/llvm-reviewers-runtime
 sycl/doc/design/spirv-extensions/ @intel/dpcpp-spirv-doc-reviewers
 sycl/doc/extensions/ @intel/dpcpp-specification-reviewers