manifest: clear `_lazydirs` in place in `_loadalllazy`...
manifest: clear `_lazydirs` in place in `_loadalllazy`
This avoid resetting the type of the dictionary in pytype eyes. This is
consistent with the way the dictionary is cleared bits by bits in
`_loadalllazy`
Having more accurate code will help pytype. We do it in advance to help
bisecting and avoid drowning them in the future type annotation noise.
