Clears previous watch inputs, if any, and then populates watch inputs from the full set of files picked up by the cache manifest.
Must be accompanied with cacheHitWatched.
pub fn writeManifestAndWatch(s: *Step, maker: *Maker, man: *Cache.Manifest) !void
pub fn writeManifestAndWatch(s: *Step, maker: *Maker, man: *Cache.Manifest) !void {
try writeManifest(s, maker, man);
try setWatchInputsFromManifest(s, maker, man);
}