treewide: more compatibility with future libknot 3.4

Dealing with knot_wire_next_label()

mentioned in merge request !1533 (merged)

I checked this with one version of the overhauled CI/CD pipeline and it seems to be working AFAICT

approved this merge request

added 22 commits

• e06dd1eb...c7f0032f - 20 commits from branch master
• a083f3fe - treewide: more compatibility with future libknot 3.4
• 67dc545b - treewide: more compatibility with future libknot 3.4

Compare with previous version

mentioned in commit fe607b35

merged

mentioned in commit eac5f249

mentioned in merge request !1539 (merged)

mentioned in commit 3cafb904