support older versions of rdkit in alignment + remove should_align

[MichelML]

Checklist:

• [x] Add tests to cover the fixed bug(s) or the new introduced feature(s) (if appropriate).
• [x] Update the API documentation is a new function is added or an existing one is deleted.
• [x] Added a news entry.
  • copy news/TEMPLATE.rst to news/my-feature-or-branch.rst) and edit it.

---

ref https://github.com/datamol-org/datamol/issues/94

[codecov[bot]]

Codecov Report

Merging #96 (e65f437) into main (75e7b31) will increase coverage by 0.00%. The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main      #96   +/-   ##
=======================================
  Coverage   83.71%   83.71%           
=======================================
  Files          48       48           
  Lines        3420     3421    +1     
=======================================
+ Hits         2863     2864    +1     
  Misses        557      557           

Flag	Coverage Δ
unittests	83.71% <100.00%> (+<0.01%)	:arrow_up:

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
datamol/align.py	100.00% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 75e7b31...e65f437. Read the comment docs.