Test with Amaranth 0.5.

Author: whitequark

.github/workflows/main.yml

@@ -21,6 +21,7 @@ jobs:
         # this version range needs to be synchronized with the one in pyproject.toml
         amaranth-version:
         - '0.4'
+        - '0.5'
         - 'git'
         allow-failure:
         - true