message: feat: exclude gaps from private mutations counting
  A follow-up of for private mutations counting.
diff: @@ -50,7 +50,7 @@ export function findPrivateMutations(node: AuspiceTreeNodeExtended, seq: Analysi
  }
  })
  - for (const [pos, refNuc] of node?.mutations ?? []) {
  + for (const [pos, refNuc] of node?.substitutions ?? []) {
  if (!mutatedPositions.has(pos) && isSequenced(pos, seq)) {
  const queryNuc = root_seq[pos] as Nucleotide
  privateMutations.push({ pos, refNuc, queryNuc })
  