Python 3.10 support

[feldlime]

Added full support of Python 3.10

[codecov]

Codecov Report

Merging #47 (07eba31) into main (9b3992e) will not change coverage.
Report is 3 commits behind head on main.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##              main       #47   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           45        45           
  Lines         2242      2212   -30     
=========================================
- Hits          2242      2212   -30     

Files	Coverage Δ
rectools/metrics/classification.py	100.00% <100.00%> (ø)
rectools/metrics/diversity.py	100.00% <100.00%> (ø)
rectools/models/dssm.py	100.00% <100.00%> (ø)
rectools/models/implicit_als.py	100.00% <100.00%> (ø)
rectools/models/implicit_knn.py	100.00% <100.00%> (ø)
rectools/utils/array_set_ops.py	100.00% <100.00%> (ø)
rectools/utils/indexing.py	100.00% <100.00%> (ø)
rectools/utils/misc.py	100.00% <100.00%> (ø)