chore: setup: lint warnings on files 'open' calls

# Requirements

requirements = []

with open('requirements/runtime.txt') as f:

with open('requirements/runtime.txt', encoding='utf8', mode='r') as f:

    requirements = [line for line in f.read().splitlines() if not line.startswith('#')]

# Long description

long_description = '' # pylint: disable=invalid-name

with open('README.md', 'r') as f:

with open('README.md', encoding='utf8', mode='r') as f:

    long_description = f.read()

# Setup configurations