Update syntax for python 3.9

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 99.96%. Comparing base (20fd449) to head (0833a4d).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## v3.0.0 #1005 +/- ## =========================================== - Coverage 100.00% 99.96% -0.04% =========================================== Files 20 20 Lines 2905 2906 +1 =========================================== Hits 2905 2905 - Misses 0 1 +1 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.