Remove build.rs

Afeter commit 5820bf6, build.rs has
no use anymore, so remove.

Signed-off-by: Jiang Liu <gerry@linux.alibaba.com>

Author: jiangliu

Cargo.toml

@@ -11,7 +11,6 @@ description = "Sampling profiler for Python programs "
 readme = "README.md"
 exclude = ["images/*", "test_programs/*"]
 license = "MIT"
-build="build.rs"
 edition="2021"
 
 [dependencies]