In order to keep the embedded and schemacs test crates building when we
update their local transient dependencies we need to use a `patch`
section.
- For `bitcoin/embedded` add `patch` section for `internals`, `hashes`
already has an entry.
- For `hashes/embedded` add `patch` section for `internals`.
- For `hashes/extendend_tests/schemars` add `patch` section for
`internals`.
FTR for direct local dependencies we use a `path` field when specifying
the dependency.
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