perf: Change link-time optimization in dev and test

This change improves the development cycle in both dev and test,
when running the same command multiple times in a row.

On my machine I can see improvements from minutes to seconds.
For example when running `cargo run` and `cargo test`.

Cargo.toml

@@ -145,12 +145,12 @@ debug-assertions = false
 
 [profile.dev]
 opt-level = 2
-lto = "thin"
+lto = "off"
 incremental = true
 
 [profile.test]
 opt-level = 2
-lto = "thin"
+lto = "off"
 incremental = true
 debug = true
 debug-assertions = true