Make Python 3.8 minimum requirement

src/ocrmypdf/__main__.py

@@ -71,6 +71,4 @@ def run(args=None):
 
 
 if __name__ == '__main__':
-    if sys.platform == 'darwin' and sys.version_info < (3, 8):
-        set_start_method('spawn')  # see python bpo-33725
     sys.exit(run())

src/ocrmypdf/subprocess/_windows.py

@@ -171,11 +171,6 @@ SHIMS = [
 def fix_windows_args(program: str, args, env):
     """Adjust our desired program and command line arguments for use on Windows"""
 
-    if sys.version_info < (3, 8):
-        # bpo-33617 - Windows needs manual Path -> str conversion
-        args = [os.fspath(arg) for arg in args]
-        program = os.fspath(program)
-
     # If we are running a .py on Windows, ensure we call it with this Python
     # (to support test suite shims)
     if program.lower().endswith('.py'):