cargo:rerun-if-changed=build.rs is redundant

https://doc.rust-lang.org/cargo/reference/build-scripts.html#cargorerun-if-changedpath

riscv-rt/build.rs

@@ -30,7 +30,5 @@ fn main() {
     // Put the linker script somewhere the linker can find it
     fs::write(out_dir.join("link.x"), include_bytes!("link.x")).unwrap();
     println!("cargo:rustc-link-search={}", out_dir.display());
-
-    println!("cargo:rerun-if-changed=build.rs");
     println!("cargo:rerun-if-changed=link.x");
 }