Don't run resolve when Package.resolved is updated

[adam-fowler]

Is your feature request related to a problem? Please describe.
I think I made a mistake when I implemented the automatic running of resolve when the Package.resolved was updated. I'm starting to think it should only occur when the Package.swift is updated.

Issues with running resolve when Package.resolved is updated include

• Rare occasions where sourcekit-lsp and vscode fight over what state it should be in.
• There have been times when I've wanted to stash the Package.resolved to change branches but it will keep getting generated making sure I cannot change branch.

Describe the solution you'd like
Remove Package.resolved FileWatcher

[plemarquand]

How would we handle the case where you have the same Package.swift between two branches, but different Package.resolved files? Switching branches wouldn't trigger a resolution and you'd end up with different dependencies than when you do a fresh checkout.

[adam-fowler]

The user can run resolve themselves. But as soon as they run a build the resolve should occur. I believe that is what occurs