Done as is single patch to make sure all the docs and CI are in sync and
correct.
We currently pin the `schemars` dependency using `<=0.8.3` as well as a
the `dyn-clone` transient dependency in the manifest (`hashes` and the
extended test crate). This is incorrect because it makes usage of the
crate klunky (or possibly impossible) if downstream users wish to use a
later version of `schemars`.
Observe also that we do not have to pin `schemars`, we do however have to pin
the `serde` crate if either `serde` or `schemars` features are enabled.
Do so in CI and document in the readme file within hashes.
Currently we have a pin remaining from the old MSRV (`syn` due to use
of `matches!`).
Fix pinning by:
- Remove pin in manifest for `schemars`
- Fix pinning for MSRV in CI and docs (this includes documenting pinning
requirements for `schemars` feature because it is related to the other
pin of `serde`) in both `hashes` readme and main repo readme.
Tobin C. Harding