Update watchexec to v5 and watchexec-signals to v4

[myanvoos]

Related to Issue #34

Previously updating watchexec to v5 leads to this error:

error[E0308]: mismatched types
  --> crates/tuono/src/watch.rs:90:46
   |
90 |         if action.signals().any(|sig| sig == Signal::Interrupt) {
   |                                       ---    ^^^^^^^^^^^^^^^^^ expected `watchexec_supervisor::Signal`, found `watchexec_signals::Signal`

This PR fixes the import issue by changing use watchexec-signals::Signal to use watchexec_supervisor::Signal.

It also updates watchexec-signals to v4 with no further errors.

[Valerioageno]

Thanks for addressing this. On my side, it panics when I try to start the dev environment on any project of the repo.

[Valerioageno]

Could you please check that the fixes work on the repositories example projects and documentation website?

[Valerioageno]

Why this change? Technically, watchexec_supervisor::Signal is just a re-export from watchexec_signals::Signal

https://docs.rs/watchexec-supervisor/latest/watchexec_supervisor/index.html#reexports

[myanvoos]

You're right - what happened was I updated watchexec to 5.0.0 first (while watchexec_signals was still on 3.0.0) and encountered the error mentioned in the PR description. Changing the import to watchexec_supervisor::Signal fixed it. But updating watchexec_signals to 4.0.0 fixes the error as well since watchexec 5.0.0 is dependent on it.

I'll revert the import back to watchexec_signals::Signal in a later commit as it's no longer necessary

[Valerioageno]

Thanks @myanvoos for addressing this!