nextpnr: Use readline 6.2
nextpnr: Use readline 6.2

litex-hub/litex-conda-compilers,timvideos/conda-misoc-lm32,litex-hub/litex-conda-eda,timvideos/conda-hdmi2usb-packages,timvideos/conda-misoc-lm32,litex-hub/litex-conda-prog,timvideos/conda-hdmi2usb-packages