chore: add code ownership rules for package management files

- Add @hevayo @gigara @kanushka as owners for package.json, lock files, and rush configuration
- Add ownership for /common/ directory to protect build and dependency infrastructure
- Ensure all dependency and build configuration changes require security review

Author: kanushka

.github/CODEOWNERS

@@ -2,6 +2,12 @@
 *.css @hevayo @gigara @tharindulak
 *.scss @hevayo @gigara @tharindulak
 .trivyignore @hevayo @gigara
+package.json @hevayo @gigara @kanushka
+package-lock.json @hevayo @gigara @kanushka
+pnpm-lock.yaml @hevayo @gigara @kanushka
+pnpm-workspace.yaml @hevayo @gigara @kanushka
+rush.json @hevayo @gigara @kanushka
+/common/ @hevayo @gigara @kanushka
 /workspaces/common-libs/ @hevayo @gigara @tharindulak
 /workspaces/mi/ @hevayo @gigara @kaumini
 /workspaces/ballerina/ballerina-core/src/interfaces/extended-lang-client.ts @hevayo @axewilledge @kanushka