fix: salsa pointer compare issue

See salsa-rs/salsa#536

There's a fix in the main stream, but that fix is using an unstable api
`std::ptr::addr_eq` which will cause compile failure in our ci.

Anyway, I decided to swicth salsa to my custom fork before it went
stable to avoid possible similar issues.

Author: Chronostasys

Cargo.lock

@@ -41,7 +41,7 @@ lsp-server = "0.7"
 serde_json = "1.0"
 rustc-hash = "1.1"
 crossbeam-channel = "0.5"
-salsa = { package = "salsa", git = "https://github.com/salsa-rs/salsa", branch = "master" }
+salsa = { package = "salsa", git = "https://github.com/Chronostasys/salsa", branch = "master" }
 enum_dispatch = "0.3"
 threadpool = { version = "1.8", optional = true }
 dunce = "1.0"