After hugo version 0.57 I noticed that a list immediately followed by a code block forces an empty line between the list and its last entry. This can be solved by inserting an non-empty line or even a comment. This was already marked as an issue in github.
My new list:
- first entry
- second entry
third entry
my nice code
Another new list with the last entry followed by "<!-- inserted to avoid incorrect list ending -->" :
- first entry
- second entry
- third entry
more nice code