chore: remove clarity coverage

[simone-stacks]

Remove the -c, --coverage option from clarity-cli and the underlying EvalHook/CoverageReporter implementation from the Clarity VM.

Why

• Clarinet already does this better (clarinet test --coverage)
• The EvalHook trait adds an extra lifetime parameter ('hooks) that propagates through GlobalContext, Environment, and OwnedEnvironment
• Clarinet is the standard tool for Clarity development
• Less lines of code we don't need to maintain

What to remove

• clarity/src/vm/coverage.rs (delete)
• EvalHook trait and hook calls in clarity/src/vm/mod.rs
• 'hooks lifetime from context structs in clarity/src/vm/contexts.rs
• Coverage params from clarity-cli (lib.rs, main.rs, README.md)

If we ever need VM hooks again, the pattern is simple and in git history.

[jcnelson]

I think that sounds reasonable at first blush.

[brice-stacks]

Clarinet uses EvalHook for various features, including its own coverage implementation, so we should not remove this trait and the associated lifetime.

[simone-stacks]

Oh you're right, I didn't think about it.
Despite EvalHook, can I proceed removing coverage?