provide v2 metadata for META.json
Among other things, this also indicates that there are no dynamic prerequisites (META.json can be relied upon for the full list of dependencies). Therefore metacpan.org can also remove "and possibly others" from the list of dependencies.
There's no need to produce meta v2 yaml as META.json is already conformed to v2. cf. https://metacpan.org/release/ISHIGAKI/JSON-PP-4.16/source/META.json#L11-14
No, the important change here is that dynamic_config changes from 1 to 0.
which requires specification as meta-spec 2, and is downconverted when generating the yaml automatically.
I think this PR should be re-opened. Making these changes does improve the metadata.