chore: Fix dependency chain for json_schema feature (#692)

sdk/Cargo.toml

@@ -25,6 +25,9 @@ exclude = ["tests/fixtures"]
 all-features = true
 rustdoc-args = ["--cfg", "docsrs"]
 
+[package.metadata.cargo-udeps.ignore]
+normal = ["unicode-ident"]
+
 [features]
 default = ["v1_api"]
 add_thumbnails = ["image"]
@@ -35,7 +38,7 @@ no_interleaved_io = ["file_io"]
 fetch_remote_manifests = []
 openssl = ["dep:openssl", "c2pa-crypto/openssl"]
 openssl_sign = ["openssl", "c2pa-crypto/openssl"]
-json_schema = ["dep:schemars"]
+json_schema = ["dep:schemars", "c2pa-crypto/json_schema"]
 pdf = ["dep:lopdf"]
 v1_api = []
 unstable_api = []
@@ -124,13 +127,13 @@ sha2 = "0.10.6"
 tempfile = "3.10.1"
 thiserror = "1.0.61"
 treeline = "0.1.0"
+unicode-ident = "=1.0.13" # Can't advance to 1.0.14 until Unicode-3.0 license is reviewed.
 url = "=2.5.2" # Can't advance to 2.5.3 until Unicode-3.0 license is reviewed.
 uuid = { version = "1.10.0", features = ["serde", "v4", "js"] }
 x509-parser = "0.16.0"
 x509-certificate = "0.21.0"
 zip = { version = "0.6.6", default-features = false }
 
-
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 ureq = "2.4.0"
 image = { version = "0.24.7", default-features = false, features = [