Fix ci workflow: Stop producing the coverage badge

[dbast]

This PR fixes the automated Github test workflow introduced in #113 ... The failure wasn't obvious as Github actions weren't activated before.

The error can be seen e.g. in this run https://github.com/hyperliquid-dex/hyperliquid-python-sdk/actions/runs/12834171538/job/35790880179

The fix is to not generated the coverage.svg badge as that is anyways currently not shown in the README anymore.

The PR now tests itself :)

Update: Seems like Action runs still need an approval ... the PR indicates below: "1 workflow awaiting approval" ... that can be configured in the repo settings: Like "Require approval for first-time contributors" or "Require approval for all external contributors" ... in https://github.com/hyperliquid-dex/hyperliquid-python-sdk/settings/actions

[traderben]

Thanks for the quick follow up! The button to approve runs is now visible

[dbast]

yay. all green :)

[dbast]

@traderben Up to you if you want to approve every run or only PRs from new contributors ... can be changed in the settings ... Action runs are normally pretty save and do not allow write access or secrets access when the are initiated from repo forks.