Unfortunately, this isn't correct according to my sources -- Italian anno < Latin annus < PIE h₂t-nó-s from a root h₂t- "to go", while ano < Latin anus < PIE *h₁eh₂no- "ring".
https://www.merriam-webster.com/dictionary/annual https://www.merriam-webster.com/dictionary/anus
https://www.etymonline.com/word/annual https://www.etymonline.com/word/anus