Update pyproject.toml

[lewisblake]

0.21.0.dev0

Change Summary

update pyproject.toml to 0.21.0.dev0

Related issue number

NA, Heiko message in chat

Checklist

• Start with a draft-PR
• The PR title is a good summary of the changes
• PR is set to AeroTools and a tentative milestone
• Documentation reflects the changes where applicable
• Tests for the changes exist where applicable
• Tests pass locally
• Tests pass on CI
• At least 1 reviewer is selected
• Make PR ready to review

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.33%. Comparing base (12ffff3) to head (d95899c).
Report is 446 commits behind head on main-dev.

Additional details and impacted files

@@            Coverage Diff            @@
##           main-dev    #1239   +/-   ##
=========================================
  Coverage     79.33%   79.33%           
=========================================
  Files           133      133           
  Lines         20284    20284           
=========================================
  Hits          16092    16092           
  Misses         4192     4192           

Flag	Coverage Δ
unittests	79.33% <ø> (ø)

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