Remove outdated doc about build parallelism (#827)

NobodyXu · web-flow · commit 9042a841c23f · 2023-07-19T23:24:59.000-07:00
diff --git a/src/lib.rs b/src/lib.rs
@@ -34,9 +34,6 @@
 //!
 //! Cargo will also set this environment variable when executed with the `-jN` flag.
 //!
-//! If `NUM_JOBS` is not set, the `RAYON_NUM_THREADS` environment variable can
-//! also specify the build parallelism.
-//!
 //! # Examples
 //!
 //! Use the `Build` struct to compile `src/foo.c`:
