applet.memory.onfi: convert to native amaranth Addresses `memory.onfi` item from #150.

applet.program.xc6s: remove unused import

applet.video.rgb_input: assorted minor fixes

applet.video.rgb_input: convert to native amaranth Addresses the `video.rgb_input` item from #150.

CI: add pypy-{3.8,3.9} and 3.11 (with failure allowed) to build matrix.

meetings: add minutes from 2023-07-02

applet.memory.floppy: convert to native amaranth Addresses `memory.floppy` item from #150.

Update gitignore Add the venv directory to the ignore set so that python environments won't show up as uncommitted files.

CI: drop py3.7 and add py3.10

README: revise Yosys + nextpnr install links