Existing listers use the is_within_bound [1] method from the base lister.
This method uses inclusive boundaries in all cases.
As some "range" task listers [2] [3] are using split_range function to create
"overlapping" ranges, this can be the concurrent insert issue cause we found [4].
This commit adapts the function split_range to make the generated ranges no
longer overlap.
[2]
https://forge.softwareheritage.org/source/swh-lister/browse/master/swh/lister/gitlab/tasks.py$37-41
[3]
https://forge.softwareheritage.org/source/swh-lister/browse/master/swh/lister/gitea/tasks.py$36-41
[4] https://sentry.softwareheritage.org/share/issue/aec9c2af347e47ea84f51ace3bfe2f25/
Related to T2577