Add patch section to test crates

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.

bitcoin/embedded/Cargo.toml

@@ -30,3 +30,6 @@ lto = true # better optimizations
 
 [patch.crates-io.bitcoin_hashes]
 path = "../../hashes"
+
+[patch.crates-io.bitcoin-internals]
+path = "../../internals"

hashes/embedded/Cargo.toml

@@ -30,3 +30,6 @@ bench = false
 codegen-units = 1 # better optimizations
 debug = true # symbols are nice and they don't increase the size on Flash
 lto = true # better optimizations
+
+[patch.crates-io.bitcoin-internals]
+path = "../../internals"

hashes/extended_tests/schemars/Cargo.toml

@@ -18,3 +18,6 @@ serde = { version = "1.0", default-features = false}
 schemars = "0.8.3"
 serde_test = "1.0"
 serde_json = "1.0"
+
+[patch.crates-io.bitcoin-internals]
+path = "../../../internals"