chore: remove stale code for conditional import of Literal

[fpgmaas]

Description

The codebase contains the following code twice:

if sys.version_info >= (3, 8):
    from typing import Literal
else:
    from typing_extensions import Literal

I believe this can be removed, since pyproject.toml specifies that the minimum Python version for the project is 3.8:

requires-python = ">=3.8"

Related Issue(s)

Documentation

[fpgmaas]

CI/CD is failing due to this issue. Merging this PR will solve it for now.