Add .devcontainer folder to CODEOWNERS

Author: oscarsj

CODEOWNERS

@@ -42,3 +42,6 @@ MODULE.bazel @github/codeql-ci-reviewers
 # Misc
 /misc/scripts/accept-expected-changes-from-ci.py @RasmusWL
 /misc/scripts/generate-code-scanning-query-list.py @RasmusWL
+
+# .devcontainer
+/.devcontainer/ @github/codeql-ci-reviewers