Fix spurious unreachable and disallow-any errors from deferred passes

[Michael0x2a]

This diff:

• FixesIncorrent "Missing return statement" in presence of bad combination of decorated function call, definition order and NoReturn #8129
• Fixesfunction call that returns Never incorrectly marked as unreachable when function that's defined later with multiple argument decorator is called #13043
• Fixes(🐞) False except contains Any when inside a function that references a variable that is defined after the function and has an inferred type #13167

For more concise repros of these various issues, see the modified test files. But in short, there were two broad categories of errors:

1. Within the deferred pass, we tend to infer 'Any' for the types of different variables instead of the actual type. This interacts badly with our unreachable and disallow-any checks and causes spurious errors.

   Arguably, the better way of handling this error is to only collect errors during the final pass. I briefly experimented with this
   approach, but was unable to find a clean, efficient, and non-disruptive way of implementing this. So, I settled for sprinkling in a few more not self.current_node_deferred checks.

2. The self.msg.disallowed_any_type(...) call is normally guarded behind a not self.chk.current_node_deferred check. However, we were bypassing this check for except block assignments because we were deliberately setting that flag to False to work around some bug. For more context, see [WIP] Fix bug with exception variable reuse in deferred node. #2290.

   It appears we no longer need this patch anymore. I'm not entirely sure why, but I'm guessing we tightened and fixed the underlying problem with deferred passes some time during the past half-decade.

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉