gh-87092: update CODEOWNERS for split of compile.c to 3 files (#103941)

Author: iritkatriel

.github/CODEOWNERS

@@ -25,6 +25,8 @@ Objects/frameobject.c         @markshannon
 Objects/call.c                @markshannon
 Python/ceval.c                @markshannon
 Python/compile.c              @markshannon @iritkatriel
+Python/assemble.c             @markshannon @iritkatriel
+Python/flowgraph.c            @markshannon @iritkatriel
 Python/ast_opt.c              @isidentical
 Lib/test/test_patma.py        @brandtbucher
 Lib/test/test_peepholer.py    @brandtbucher