no_adjacent_strings_in_list tests should include list patterns

[srawlins]

Child issue of #58837 I suppose.

I think there should be a test case like:

List<String?> row = ...

// If the first column is 'one', and the second is 'two', we expect to have a name after it.
switch (row) {
  case ['one' 'two', var name!]:
    // name is a non-nullable string here.
}