build: suppress harmless rollup warnings from @actions dependencies

build: suppress harmless rollup warnings from @actions dependencies This commit adds an `onwarn` handler to `rollup.config.ts` to suppress `THIS_IS_UNDEFINED` and `CIRCULAR_DEPENDENCY` warnings originating from `@actions/*` packages. These warnings are caused by the bundling of CommonJS modules (which use `this` at the top level and may have internal circular refs) into an ESM output. The runtime behavior is correct, so suppressing these specific warnings cleans up the build output. Co-authored-by: hussainweb <1040271+hussainweb@users.noreply.github.com>