Breaking Changes 55267 and 55508: Change the types of isTruthy, not, and importModule in dart:js_interop

[Srujan Gaddam]

`isTruthy` and `not` both return a `bool` in `dart:js_interop`. In order to keep these operators performant and consistent with other operators, they are being changed to return a `JSBoolean`.

`importModule` takes a `String` representing a module and then invokes the JavaScript dynamic import function with it as a parameter. The dynamic import function accepts more JavaScript values than just strings, however, and should accept types like `TrustedScriptURL`s. In order to allow such values to be passed to `importModule`, `importModule` will be changed to accept a `JSAny`.

See https://github.com/dart-lang/sdk/issues/55267 and https://github.com/dart-lang/sdk/issues/55508 for more details. If these breaking changes pose a severe problem, please leave a comment on these issues.

[Srujan Gaddam]

These changes have been implemented in https://github.com/dart-lang/sdk/commit/1550539558218b0a8fee36791ef7b4bd5ee32f6a and https://github.com/dart-lang/sdk/commit/0b761229cc86d727236a363e1ae5ea673f93afba.