Fix edge-case in identify 'end' upper-bound

Just my luck, this was found immediately in the CI, right when I uploaded the project thinking I was done. Thankfully the fix is easy and (in hindsight) quite obvious.
Fix Meson install
2024-08-24 20:59:14 +01:00 · 2024-08-24 20:37:27 +01:00 · 2024-08-24 20:32:14 +01:00
From what I could find, the rules of the assignment seem to be:

1. Restrict oneself to at most *one* O(log(N)) call, and otherwise use
   constant time operations on the map.
2. Don't use more operations than strictly necessary on `K` and `V`.
3. Prefer simplicity to performance.

I think my solution would fair well under those constraints.