Segger J-Link Supply Adapter
Yes.

J-Link has buffers (or level converters) that you can provide with any voltage between 1.8 and 5V. This voltage can come from anywhere - from the target, from an LDO on the J-Link side, from another PSU. It hardly matters as long as the logic levels of the target MCU match the logic levels of J-Link buffers.

You could even inject power via Vtref to the target board (depending on the exact design).

The linked adapter does exactly what is advertized - it allows to generate the voltages on the J-Link side and get rid of one wire connecting to the target board.