src/meta-tensorflow:python3-opt-einsum: Use ConfigParser instead of S…

…afeConfigParser

The SafeConfigParser class will be renamed to ConfigParser in Python
3.12 [1]. This alias will be removed in future versions.So we can use
ConfigParser directly instead.

[1] python/cpython#89336

Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>