Explanation: We need to watch for changes to Package.resolved so that we can update the dependency checkouts in .index-build when the user runs swift package update.
Scope: Background indexing when the user updates package dependencies
Risk: Low, this uses the same code path that we use to watch for changes to Package.swift
Package.resolved
so that we can update the dependency checkouts in.index-build
when the user runsswift package update
.Package.swift