improvement: Support generic actions without a return type. (#238) #1240

Job	Run time
ash-ci / mix igniter.upgrade	6s
ash-ci / audit	44s
ash-ci / mix deps.get	24s
ash-ci / MIX_ENV=test mix.compile	45s
ash-ci / mix credo --strict	49s
ash-ci / mix docs	30s
ash-ci / mix ash.codegen --check	0s
ash-ci / MIX_ENV=dev mix.compile	26s
ash-ci / Deploy docs to GitHub pages.	1s
ash-ci / mix format --check-formatted	40s
ash-ci / mix dialyzer	3m 44s
ash-ci / mix sobelow	39s
ash-ci / mix spark.cheat_sheets --check	43s
ash-ci / mix spark.formatter --check	49s
ash-ci / mix test	1m 16s
ash-ci / mix deps.unlock --check-unused	50s
ash-ci / Release	0s
	12m 26s

Provide feedback