Allow compilation for target wasm32-unknown-unknown without js-sys

Also removes the unused dependency on `iota-crypto` (which also had
a dependency on `js-sys` through the `random` feature).

Author: Frederik Rothenberger

identity_core/Cargo.toml

@@ -12,7 +12,6 @@ rust-version.workspace = true
 description = "The core traits and types for the identity-rs library."
 
 [dependencies]
-iota-crypto = { version = "0.23", default-features = false, features = ["ed25519", "random", "sha", "x25519", "std"] }
 multibase = { version = "0.9", default-features = false, features = ["std"] }
 serde = { workspace = true, features = ["std"] }
 serde_json = { workspace = true, features = ["std"] }
@@ -22,8 +21,8 @@ time = { version = "0.3.23", default-features = false, features = ["std", "serde
 url = { version = "2.4", default-features = false, features = ["serde"] }
 zeroize = { version = "1.6", default-features = false }
 
-[target.'cfg(all(target_arch = "wasm32", not(target_os = "wasi")))'.dependencies]
-js-sys = { version = "0.3.55", default-features = false }
+[target.'cfg(all(target_arch = "wasm32", not(target_os = "wasi"), not(feature = "custom_time")))'.dependencies]
+js-sys = { version = "0.3.55", default-features = false, optional = true }
 
 [dev-dependencies]
 proptest = { version = "1.0.0" }