The documentation of the runner context is missing from https://forgejo.org/docs/next/user/actions/reference/#contexts. I could confirm that at least ${{runner.os}} and ${{runner.arch}} are set. Unfortunately I was unable to navigate the code of the runner beyond map[string]any so I don't know which other variables exist and as such am unable to add the context to the documentation myself.
The documentation of the `runner` context is missing from https://forgejo.org/docs/next/user/actions/reference/#contexts. I could confirm that at least `${{runner.os}}` and `${{runner.arch}}` are set. Unfortunately I was unable to navigate the code of the runner beyond `map[string]any` so I don't know which other variables exist and as such am unable to add the context to the documentation myself.