…1152)

core._find_matches seeds candidate_idx = query_idx and then breaks when
D[candidate_idx] > atol + max_distance, so it relies on D[query_idx] == 0.
core.mass_absolute establishes that, but aamp_match never passed query_idx to
it, unlike motifs.match which passes it to core.mass.

query_idx was added to core.mass and core.mass_absolute in #860; #856 wired it
into core.mass from motifs.match the next day, but aamp_motifs.py was not
updated. core.mass_absolute's query_idx branches have been unreachable since,
which is why they carry `# pragma: no cover`. They are now covered, so the
pragmas are removed.

For a correct self-join the fix is a no-op: cdist returns exactly 0.0 for the
identical row, so D[query_idx] was already the minimum. What it restores is the
"self-match is returned first" guarantee and the "Subsequences `Q` and
`T[query_idx:query_idx+m]` are different" warning when query_idx does not
describe Q -- neither of which could happen on the non-normalized path.