Decouple serde from its derive crate

By not activating the `derive` feature on `serde`, the compilation speed
can be improved by a lot. This is because `serde` can then compile in
parallel to `serde_derive`, allowing it to finish compilation possibly
even before `serde_derive`, unblocking all the crates waiting for
`serde` to start compiling much sooner.

As it turns out the main deciding factor for how long the compile time of a
project is, is primarly determined by the depth of dependencies rather
than the width. In other words, a crate's compile times aren't affected
by how many crates it depends on, but rather by the longest chain of
dependencies that it needs to wait on. In many cases `serde` is part of
that long chain, as it is part of a long chain if the `derive` feature
is active:

`proc-macro2` compile build script > `proc-macro2` run build script >
`proc-macro2` > `quote` > `syn` > `serde_derive` > `serde` >
`serde_json` (or any crate that depends on serde)

By decoupling it from `serde_derive`, the chain is shortened and compile
times get much better.

Check this issue for a deeper elaboration:
serde-rs/serde#2584

For `samply` I'm seeing a reduction from 5.43s to 3.70s when compiling
`fxprof-processed-profile` in `release` mode.

Author: CryZe

Cargo.lock

@@ -12,7 +12,8 @@ readme = "README.md"
 [dependencies]
 bitflags = "2.0"
 serde_json = "1.0"
-serde = { version = "1.0", features = ["derive"] }
+serde = "1.0.188"
+serde_derive = "1.0.188"
 debugid = "0.8.0"
 fxhash = "0.2.1"
 

fxprof-processed-profile/Cargo.toml

@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use serde::Serialize;
+use serde_derive::Serialize;
 use serde_json::Value;
 
 use super::timestamp::Timestamp;

fxprof-processed-profile/src/markers.rs

@@ -11,7 +11,8 @@ readme = "README.md"
 
 [dependencies]
 serde_json = "1.0"
-serde = { version = "1.0", features = ["derive"] }
+serde = "1.0.188"
+serde_derive = "1.0.188"
 debugid = "0.8.0"
 
 [dev-dependencies]

gecko_profile/Cargo.toml

@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use serde::Serialize;
+use serde_derive::Serialize;
 use serde_json::{json, Value};
 use std::time::Instant;
 

gecko_profile/src/markers.rs

@@ -16,7 +16,8 @@ send_futures = ["samply-symbols/send_futures"]
 [dependencies]
 samply-symbols = { version = "0.20.0", path = "../samply-symbols" }
 thiserror = "1.0.26"
-serde = { version = "1.0.126", features = ["derive"] }
+serde = "1.0.188"
+serde_derive = "1.0.188"
 serde_json = "1.0.64"
 serde_tuple = "0.5.0"
 yaxpeax-arch = { version = "0.2.7", default-features = false }

samply-api/Cargo.toml

@@ -1,4 +1,4 @@
-use serde::Deserialize;
+use serde_derive::Deserialize;
 
 #[derive(Deserialize, Debug)]
 #[serde(rename_all = "camelCase")]

samply-api/src/asm/request_json.rs

@@ -1,4 +1,4 @@
-use serde::Deserialize;
+use serde_derive::Deserialize;
 
 #[derive(Deserialize, Debug)]
 #[serde(rename_all = "camelCase")]

samply-api/src/source/request_json.rs

@@ -1,4 +1,4 @@
-use serde::Deserialize;
+use serde_derive::Deserialize;
 
 #[derive(Deserialize, Debug)]
 #[serde(untagged)]

samply-api/src/symbolicate/request_json.rs

@@ -1,6 +1,6 @@
 use std::collections::HashMap;
 
-use serde::Serialize;
+use serde_derive::Serialize;
 
 #[derive(Serialize, Debug)]
 pub struct Response {