fix(rollup): update cwc rollup config (carbon-design-system#9854)

### Description

Update `carbon-web-components` rollup config to suppress the following warning:
```
@rollup/plugin-replace: 'preventAssignment' currently defaults to false. It is recommended to set this option to `true`, as the next major version will default this option to `true`.
```

### Changelog

**Changed**

- set `preventAssignment: true` 

<!-- React and Web Component deploy previews are enabled by default. -->
<!-- To enable additional available deploy previews, apply the following -->
<!-- labels for the corresponding package: -->
<!-- *** "test: e2e": Codesandbox examples and e2e integration tests -->
<!-- *** "package: services": Services -->
<!-- *** "package: utilities": Utilities -->
<!-- *** "RTL": React / Web Components (RTL) -->
<!-- *** "feature flag": React / Web Components (experimental) -->

Author: kennylam

carbon-web-components/packages/carbon-web-components/tools/get-rollup-config.js

@@ -176,6 +176,7 @@ function getRollupConfig({
       }),
       replace({
         'process.env.NODE_ENV': JSON.stringify(mode),
+        preventAssignment: true,
       }),
       ...(mode === 'development'
         ? [license(licenseOptions)]