Fix build lock not releasing

[TheSpyder]

I tried a few different ways to fix this, but in the end just moving the watch mode exit handlers out to run all the time was the best approach.

Fixes #5590.

[cristianoc]

Any thought on why moving them was necessary?
Not familiar with this code, so asking basic questions.

[TheSpyder]

If you expand the diff a bit, previously the listeners were inside a function that only runs in watch mode.

Now they are set up before deciding what to do based on the arguments.

[cristianoc]

Makes perfect sense.
Thanks for the fix!