Remove implicit optional dependency features (#2512)

* remove implicit optional dependency features

* switch to new features in desktop, router and signals crates

packages/core/Cargo.toml

@@ -43,7 +43,7 @@ features = [
 
 [features]
 default = []
-serialize = ["serde"]
+serialize = ["dep:serde"]
 
 [package.metadata.docs.rs]
 cargo-args = ["-Zunstable-options", "-Zrustdoc-scrape-examples"]