until which year/version of MacBook Pro apple continue to provide updates
I have old MacBook Pro bought in 2018 and I wanted to know whether I would receive the 2023 OS updates
MacBook (2017)
The answer is yes. Please read Update macOS on Mac - Apple Support.
Apple typically provides software updates and support for very approximately seven years. Read Obtaining service for your Apple product after an expired warranty - Apple Support. It lists "obsolete" Macs as well as those on the cusp of becoming so.