have rollup error when we’re using deprected config options

currently it just warns, which we won’t see because of Nx’s logging. plus it’s better to ready to upgrade, rather than needing to make the changes (we’ll need to one day…).

tools/nx-plugins/npm-package/build/index.ts

@@ -47,6 +47,7 @@ const getRollupConfig = (
 	}
 
 	return {
+		strictDeprecations: true,
 		output: {
 			dir: `${options.outputPath}/${format}`,
 			format,