TrustedScriptURL is not defined in Firefox and scriptlet does not work correctly.

Steps to reproduce:

1. Add to user rules:

example.org#%#//scriptlet('prevent-element-src-loading', 'script', 'test.js')

2. Go to - https://example.org/
3. Open devtools and run in console:

(() => {
    const script = document.createElement('script');
    script.src = 'test.js';
    document.body.appendChild(script);
})();

There is an error: Uncaught ReferenceError: TrustedScriptURL is not defined.

Screenshot

The problem seems to be here:

if (policy && policy.isSupported && urlValue instanceof TrustedScriptURL) {