Fortunately it's becoming more common to provide permalinks to gitlab etc so people can access the actual version of code used in a paper. That being said having some incentives to reward this practice would help speed up adoption.

Part of the blame for incorrect code also falls on reviewers. If someone agrees to peer review a paper, that should include running the code as part of the general scrutiny. If someone finds a bug after publication, they should let the appropriate people know so an errata can be published.