PEP 825: add @rgommers to CODEOWNERS

Per #5171 (comment).

Signed-off-by: Michał Górny <mgorny@quansight.com>

Author: mgorny

.github/CODEOWNERS

@@ -702,8 +702,8 @@ peps/pep-0821.rst  @JelleZijlstra
 peps/pep-0822.rst  @methane
 peps/pep-0823.rst  @gvanrossum
 peps/pep-0824.rst  @gvanrossum
-peps/pep-0825/     @warsaw @dstufft
-peps/pep-0825.rst  @warsaw @dstufft
+peps/pep-0825/     @warsaw @dstufft @rgommers
+peps/pep-0825.rst  @warsaw @dstufft @rgommers
 peps/pep-0826.rst  @savannahostrowski
 peps/pep-0827.rst  @1st1
 peps/pep-0828.rst  @ZeroIntensity