write and update the netrc with safe perms

internal/netrc/netrc.go

@@ -132,5 +132,8 @@ func write(path string, entries []entry) error {
 		fmt.Fprintf(&b, "machine %s\npassword %s\n", e.machine, e.password)
 	}
 
-	return os.WriteFile(path, []byte(b.String()), 0600)
+	if err := os.WriteFile(path, []byte(b.String()), 0600); err != nil {
+		return err
+	}
+	return os.Chmod(path, 0600)
 }