[TRT EP Perf Tool] Add annotations import to python script to support annotations on Python 3.8 (#23466)
### Description
Adds `from __future__ import annotations` to python script to support
annotations on Python 3.8.
### Motivation and Context
Pipeline that runs this script is using Ubuntu 20.04's default python
version (3.8), which does not support annotations unless one imports
from __future__.