I can see you are on Linux kernel 6.11. The driver you tried to build just got this week merged the kernel patches to add support for Fairwaves XTRX hardware revision 3 and 4.
Fairwaves XTRX hardware revision 5 (after FPGA firmware update to LimeSDR) and the LimeSDR XTRX can both only be used with the new developed LimeSuiteNG kernel driver.