fix(core, web): fix an incompatibility with Flutter Beta that would occur when calling method on TrustedScriptURL

[Lyokone]

Description

As per documentation:
The representation type of all JavaScript objects for extension types.

This is the supertype of all JS objects, but not other JS types, like primitives. See https://dart.dev/web/js-interop for more details on how to use JS interop.

Related Issues

closes #12242

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