chore: remove comment (#6463)

## Description

Closes #6209 
It looks like the compiler actually doesn't cache anything between
builds, so this issue can be closed.

## Checklist

- [ ] I have linked to any relevant issues.
- [ ] I have commented my code, particularly in hard-to-understand
areas.
- [ ] I have updated the documentation where relevant (API docs, the
reference, and the Sway book).
- [ ] If my change requires substantial documentation changes, I have
[requested support from the DevRel
team](https://github.com/FuelLabs/devrel-requests/issues/new/choose)
- [ ] I have added tests that prove my fix is effective or that my
feature works.
- [ ] I have added (or requested a maintainer to add) the necessary
`Breaking*` or `New Feature` labels where relevant.
- [ ] I have done my best to ensure that my PR adheres to [the Fuel Labs
Code Review
Standards](https://github.com/FuelLabs/rfcs/blob/master/text/code-standards/external-contributors.md).
- [ ] I have requested a review from the relevant team or maintainers.

forc-pkg/src/pkg.rs

@@ -2336,8 +2336,6 @@ pub fn build(
         let manifest = &plan.manifest_map()[&pkg.id()];
         let program_ty = manifest.program_type().ok();
 
-        // TODO: Only print "Compiling" when the dependency is not already compiled.
-        // https://github.com/FuelLabs/sway/issues/6209
         print_compiling(
             program_ty.as_ref(),
             &pkg.name,