MRG: chrono version pin

[bluegenes]

To install sourmash from mastiff branch in pyo3-branchwater, I need to bump chrono back to 0.4.28 (from 0.4.31) to avoid incompatibilities with piz.

but maybe you have a better solution, @luizirber?

[codecov]

Codecov Report

Merging #2798 (b561e7c) into lirber/mastiff (3a13ab2) will not change coverage.
The diff coverage is n/a.

@@               Coverage Diff               @@
##           lirber/mastiff    #2798   +/-   ##
===============================================
  Coverage           85.70%   85.70%           
===============================================
  Files                 135      135           
  Lines               15367    15367           
  Branches             2621     2621           
===============================================
  Hits                13170    13170           
  Misses               1896     1896           
  Partials              301      301           

Flag	Coverage Δ
hypothesis-py	25.82% <ø> (ø)
python	92.85% <ø> (ø)
rust	55.50% <ø> (ø)

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

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[ctb]

I think you'll need to merge #2799 into this, too, to get the tests to pass.

[bluegenes]

I think you'll need to merge #2799 into this, too, to get the tests to pass.

done, thanks!