[OPIK-7036] [INFRA] chore: add CODEOWNERS entry for .github/actions/ (#7176)

Mirror the /.github/workflows/ ownership so comet-devops is a required
code owner on changes under .github/actions/. Without this, the directory
fell back to the catch-all and DevOps could not gate their own actions.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: JetoPistola

.github/CODEOWNERS

@@ -11,6 +11,7 @@
 *.mdx @comet-ml/product @comet-ml/comet-opik-devs
 
 /.github/ISSUE_TEMPLATE/ @comet-ml/product @comet-ml/comet-opik-devs
+/.github/actions/ @comet-ml/comet-devops @comet-ml/comet-qa @comet-ml/comet-opik-devs
 /.github/workflows/ @comet-ml/comet-devops @comet-ml/comet-qa @comet-ml/comet-opik-devs
 
 /apps/opik-documentation/ @comet-ml/product @comet-ml/comet-opik-devs