Revert "build.rs: Remove Cargo.lock"

This reverts commit 1c4a991.

`cargo package` works fine without this cleanup now.

Author: vadorovsky

build.rs

@@ -10,16 +10,6 @@ fn main() {
         .expect("Unable to parse 'llvm-sys' crate")
         .write_declarations(&std::path::PathBuf::from(out_dir).join("llvm_gen.rs"))
         .expect("Unable to write generated LLVM declarations");
-
-    // Workaround for `cargo package`
-    // `cargo metadata` creates a new Cargo.lock file, which needs removing
-    let manifest_dir = std::env::var_os("CARGO_MANIFEST_DIR").unwrap();
-    let cargo_lock = std::path::PathBuf::from(manifest_dir).join("Cargo.lock");
-    if let Err(err) = std::fs::remove_file(&cargo_lock) {
-        if err.kind() != std::io::ErrorKind::NotFound {
-            panic!("failed to delete {}: {err}", cargo_lock.display());
-        }
-    }
 }
 
 mod llvm {