build: update codeowners-validator to 0.6

PR-URL: #40307
Reviewed-By: Mary Marchini <oss@mmarchini.me>

Author: iam-frankqiu

.github/workflows/linters.yml

@@ -120,7 +120,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - uses: mszostok/codeowners-validator@v0.4.0
+      - uses: mszostok/codeowners-validator@v0.6.0
         with:
           checks: "files,duppatterns"
   lint-pr-url: