bump lstchain version in readme

[codecov[bot]]

Codecov Report

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

Comparison is base (6507bdd) 72.66% compared to head (a97a7ca) 72.66%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1214 +/- ## ======================================= Coverage 72.66% 72.66% ======================================= Files 132 132 Lines 13648 13648 ======================================= Hits 9917 9917 Misses 3731 3731 ```

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