"Intersex" is a misleading term that's been phased out in favor of DSD (https://en.wikipedia.org/wiki/Disorders_of_sex_development). Every person is still male or female.
Women have a right to sex-specific sports, and anyone that doesn't qualify is free to compete in the men's leagues.
Since I'm rate limited, to respond to comment below:
That has been the definition for far longer than any current culture war. Right wingers might be latching onto it now, but broken clocks and all that.
To be slightly more specific, because you think you've found a gotcha, it's the gamete size one would or should produce. Biologists are well aware that there can be disorders of development.