Why has coverage been locked to `==4.0.3` for two years? Why not `>=4.0.0`?

If I add localstack to my pipenv, I can't lock because of this unnecessary dependency.
def __init__(self, cmd, params={}, outfile=None, env_vars={}, stdin=False,
            quiet=True, inherit_cwd=False):
        self.cmd = cmd
        self.process = None
        self.outfile = outfile or os.devnull
        self.stdin = stdin
        self.env_vars = env_vars
        self.inherit_cwd = inherit_cwd
        FuncThread.__init__(self, self.run_cmd, params, quiet=quiet)
    def run_cmd(self, params):
        def convert_line(line):
            line = to_str(line)
            return line.strip() + '\r\n'
        try:
            self.process = run(self.cmd, asynchronous=True, stdin=self.stdin, outfile=self.outfile,
                env_vars=self.env_vars, inherit_cwd=self.inherit_cwd)
            if self.outfile:
                if self.outfile == subprocess.PIPE:
                    
                    for line in iter(self.process.stdout.readline, ''):
                        if not (line and line.strip()):
                            time.sleep(0.1)