Patch the action_dispatch executor to report rendered exceptions

[fractaledmind]

Resolves #12

[holman]

Now I'm seeing this:

Puma caught this error: super: no superclass method `call' for #<ActionDispatch::Executor:0x000000010646e310
[...]

[fractaledmind]

I really don't want to have to put a workaround into this gem.

I have finished my investigation and I wrote a detailed explanation of what is happening: rails/rails#51002 (comment)

Takeaway: there is definitely an issue here, and Rails applications will not report errors that occur within the HTTP lifecycle unless reloading is enabled.

Hopefully we can get a resolution in upstream Rails instead of this still-not-working hack.