chore: update coveralls workflow to fetch commit history

[saiponnada]

Problem

In the context of GitHub Actions, the actions/checkout action supports the fetch-depth parameter to control how much history is fetched when checking out the repository. Default value of fetch-depth is 1 which gives access to only latest commit.

Solution

But, Coveralls needs to access the commit history to generate accurate coverage reports and associate them with the correct commits. If only the latest commit is fetched (fetch-depth: 1), Coveralls might not be able to find the necessary commit information, leading to errors like "Not a valid object name." Hence setting to 0 to fetch entire commit history.