CI: Enable Python 3.10 testing of Conda package

This works now.

Author: victorlin

.github/workflows/ci.yaml

@@ -213,7 +213,7 @@ jobs:
         python:
           - '3.8'
           - '3.9'
-          # XXX TODO: Add 3.10 here once supported by Conda/Bioconda/Conda Forge.
+          - '3.10'
     runs-on: ${{ matrix.os }}
     defaults:
       run: