Bump async-solipsism from 0.7 to 0.8 (#192)

Author: Marenz

pyproject.toml

@@ -102,7 +102,7 @@ dev-pytest = [
   "frequenz-repo-config[extra-lint-examples] == 0.13.5",
   "pytest-mock == 3.14.1",
   "pytest-asyncio == 1.1.0",
-  "async-solipsism == 0.7",
+  "async-solipsism == 0.8",
   "time-machine == 2.16.0",
   "hypothesis == 6.135.20",
   "frequenz-client-dispatch[cli]",