A lot of our “standard” or “common” BLF drivers can do 7V with minor adjustment (LDO or zener diode added to protect the MCU). In addition, there are buck and boost drivers available that could make 7V for you. The more unusual part is the 100mA current rate. Even the humble AMC7135 current regulator has a standard output of 350mA. You could remove all the chips from a normal AMC7135 regulated driver and solder a single resistor in place, I suppose. But, I wouldn’t know what resistor value to recommend. It depends on the available full voltage output of the driver.
You could try a laser driver as some of those have trim pots. Not totally sure it would go down to 100ma but it should boost the voltage enough. I used a laser driver to light up an mtg2 once.
Voltage in the spex is “typical”, ie, you don’t need to apply 7.00V to it. You apply the 100mA drive current, and the voltage across the LED would probably be 7V(ish), but could be as low as 5V or as high as 8V.
Probably would be easiest to use a boost driver for a “6V” LED, but you’d have to actually replace the sense-resistor for a larger value (ie, not just tack-solder another resistor on top of the existing one).