Is it possible to program a Cyclone 10 LP FPGA evaluation kit using a RPI?

if you have some GPIOs left, it's only a few lines of C to program the FPGA with a .rbf from there with any µC:

GPIO &= ~FPGA_CLOCK;                 /* FPGA clock => low */
 
    /* pulling FPGA_CONFIG to low resets the FPGA */
    GPIO &= ~FPGA_CONFIG;                /* FPGA config => low */
    wait(10);                                           /* give it some time to do its reset stuff */
 
    while ((GPIO & FPGA_STATUS) && (GPIO & FPGA_CONF_DONE));
 
    GPIO |= FPGA_CONFIG;                 /* pull FPGA_CONFIG high to start config cycle */
    while (!(GPIO & FPGA_STATUS))
        ;                                               /* wait until status becomes high */
 
    fpga_data = (uint8_t *) FPGA_FLASH_DATA;
    do
    {
        uint8_t value = *fpga_data++;
        for (i = 0; i < 8; i++, value >>= 1)
        {
            if (value & 1)
            {
                /* bit set -> toggle DATA0 to high */
                GPIO |= FPGA_DATA0;
            }
            else
            {
                /* bit is cleared -> toggle DATA0 to low */
                GPIO &= ~FPGA_DATA0;
            }
            /* toggle DCLK -> FPGA reads the bit */
            GPIO |= FPGA_CLOCK;
            GPIO &= ~FPGA_CLOCK;
        }
    } while ((!(GPIO & FPGA_CONF_DONE)) && (fpga_data < fpga_flash_data_end));