manifest: align some vfs option access on the fact we might not have options This make the usage consistent with the other option. Caught by pytype.

manifest: adds some type things for manifestdict.added This appeases pytype.

manifest: type and fix unhexlify Some part of that function seems to date back from Python 2. It raise question about whether this function is useful or not, but let us just fix it for now. This was caught by pytype.

docker-pytype: use version v2.1 of the CI image It use a more recent pytype as far as I understand.

context: some gratuitous documentation improvement I wrote it as I was reading the code.

profiling: add a py-spy profiling backend The recommended way to use this backend is by setting the config `profiling.output` to point to a file because py-spy output is not human-readable.

copytracing: fix a bug in an edge case in metadata.compute_all_files_changes