Remove NOTIFY_FD after reading it

src/main.rs

@@ -323,6 +323,7 @@ fn notify_fd() -> anyhow::Result<()> {
         Err(env::VarError::NotPresent) => return Ok(()),
         Err(err) => return Err(err.into()),
     };
+    env::remove_var("NOTIFY_FD");
     let mut notif = unsafe { File::from_raw_fd(fd) };
     notif.write_all(b"READY=1\n")?;
     Ok(())