Allow hyper_serde to only depend on serde_core for potentially faster compile times. (#39467)

Serde_core was released which has all the traits and allows some crates
to have parallel compile times.
More information can be found here:
https://github.com/serde-rs/serde/tree/master/serde_core
serde_bytes already depends on on serde_core. Additionally added serde
and serde_core to dependabot group.

Signed-off-by: Narfinger <Narfinger@users.noreply.github.com>

Testing: Compilation is the test.

---------

Signed-off-by: Narfinger <Narfinger@users.noreply.github.com>

.github/dependabot.yml

@@ -38,6 +38,10 @@ updates:
     objc2-related:
       patterns:
         - "objc2*"
+    serde-related:
+      patterns:
+        - "serde"
+        - "serde_core"
     servo-media-related:
       patterns:
         - "servo-media*"

Cargo.lock

@@ -4051,6 +4051,7 @@ dependencies = [
  "mime",
  "serde",
  "serde_bytes",
+ "serde_core",
  "serde_test",
 ]
 

Cargo.toml

@@ -130,6 +130,7 @@ script_traits = { path = "components/shared/script" }
 selectors = { git = "https://github.com/servo/stylo", branch = "2025-09-02" }
 serde = "1.0.226"
 serde_bytes = "0.11"
+serde_core = "1.0.226"
 serde_json = "1.0"
 servo-media = { git = "https://github.com/servo/media" }
 servo-media-dummy = { git = "https://github.com/servo/media" }

components/hyper_serde/Cargo.toml

@@ -21,8 +21,9 @@ headers = { workspace = true }
 http = { workspace = true }
 hyper = { workspace = true }
 mime = { workspace = true }
-serde = { workspace = true }
 serde_bytes = { workspace = true }
+serde_core = { workspace = true }
 
 [dev-dependencies]
+serde = { workspace = true }
 serde_test = "1.0"

components/hyper_serde/lib.rs

@@ -73,10 +73,10 @@ use http::HeaderMap;
 use hyper::header::{HeaderName, HeaderValue};
 use hyper::{Method, StatusCode, Uri};
 use mime::Mime;
-use serde::de::{self, Error, MapAccess, SeqAccess, Visitor};
-use serde::ser::{SerializeMap, SerializeSeq};
-use serde::{Deserialize, Deserializer, Serialize, Serializer};
 use serde_bytes::{ByteBuf, Bytes};
+use serde_core::de::{self, Error, MapAccess, SeqAccess, Visitor};
+use serde_core::ser::{SerializeMap, SerializeSeq};
+use serde_core::{Deserialize, Deserializer, Serialize, Serializer};
 
 /// Deserialises a `T` value with a given deserializer.
 ///
@@ -164,7 +164,7 @@ pub struct Ser<'a, T: 'a> {
 
 impl<'a, T> Ser<'a, T>
 where
-    Ser<'a, T>: serde::Serialize,
+    Ser<'a, T>: serde_core::Serialize,
 {
     /// Returns a new `Ser` wrapper.
     #[inline(always)]