Code coverage: Update Python version

[codecov-commenter]

Codecov Report

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

Project coverage is 89.53%. Comparing base (53c3964) to head (7bdb507).

:exclamation: Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1420 +/- ## ========================================== + Coverage 89.41% 89.53% +0.11% ========================================== Files 52 52 Lines 7744 7813 +69 ========================================== + Hits 6924 6995 +71 + Misses 820 818 -2 ``` | [Flag](https://app.codecov.io/gh/lark-parser/lark/pull/1420/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=lark-parser) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/lark-parser/lark/pull/1420/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=lark-parser) | `89.53% <ø> (+0.11%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=lark-parser#carryforward-flags-in-the-pull-request-comment) to find out more.

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