n2 (a reimplemntation of ninja) adds a check that depfiles only add
dependencies on source files, not generated files, because generated
files are not guaranteed to exist before an action runs if there isn't
an explicit dependency between the two.
This is the case for our glob result files. However, we can rework the
build so that they're directly depended on instead of using a depfile.
Bug: 318434287
Test: rm -rf out && m nothing && m nothing
Change-Id: I513fa5536136e6bf19c347710f0722d696199612
8c0b11ef79