Sliding doors need a header track. Ergo, not really frameless.

Do a Google search for frameless glass shower bypass doors. There are a number of options.

Live-wire-oak, the doors themselves are frameless.

I realize that the doors do not have metal frames around them. But some people view the all glass installations of the pivot doors with just the hinges and don't realize that a sliding door won't be as clean of a look because of the needed hardware. The OP needs to be aware of the difference in looks achieved.

There are options besides the traditional enclosure frames that have the clean look of swinging door shower enclosures.