feat(aio): say prompt management is free in prompts empty state (#89789)

Co-authored-by: posthog[bot] <206114724+posthog[bot]@users.noreply.github.com>
Co-authored-by: Carlos Marchal <carlos@posthog.com>
Co-authored-by: carlos-marchal-ph <228468567+carlos-marchal-ph@users.noreply.github.com>