Tflite

What's Changed
* Update to TensorFlow V2.18.0 by ebraheemabbas in https://github.com/zhenhuaw-me/tflite/pull/21

New Contributors
* ebraheemabbas made their first contribution in https://github.com/zhenhuaw-me/tflite/pull/21

**Full Changelog**: https://github.com/zhenhuaw-me/tflite/compare/v2.10.0...v2.18.0

* For TensorFlow 2.4.0
* Enhancements
* `tflite.opcode2name()`: get the type name of given opcode.
* `tflite.BUILTIN_OPCODE2NAME`: a dict that maps the opcode to name of all the builtin operators.
* Compatibility Handling
* `tflite.OperatorCode.BuiltinCode()`: maintains API compability in 2.4.0, see README.md.