fix: Add required dev dependency for CAWG X.509 example (#1029)

Author: scouten-adobe

cawg_identity/Cargo.toml

@@ -62,6 +62,7 @@ wasm-bindgen = "0.2.95"
 
 [dev-dependencies]
 anyhow = "1.0.97"
+c2pa = { path = "../sdk", version = "0.49.1", features = ["file_io"] }
 serde = { version = "1.0.197", features = ["derive"] }
 
 [target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]