CI: unignore DeprecationWarning With the move away from amaranth.compat almost complete, the tests are now free from deprecation warnings.

access.direct.multiplexer: remove leftover compat names

gateware: remove top-level compat leftovers

CI: remove allow-failure from 3.11

software: convert core modules to native amaranth

gateware.fx2_crossbar: convert to native amaranth

gateware.analyzer, target.analyzer: convert to native amaranth

software: squash a few `ResourceWarning`s

gateware.mpsse: remove

software: fix coroutines on Python 3.11 Fixes #297.