Upload code coverage only from master

[scap3yvt]

Fixes #ISSUE_NUMBER

Proposed Changes

Checklist

• [ ] CONTRIBUTING guide has been followed.
• [ ] PR is based on the current GaNDLF master .
• [ ] Non-breaking change (does not break existing functionality): provide as many details as possible for any breaking change.
• [ ] Function/class source code documentation added/updated (ensure typing is used to provide type hints, including and not limited to using Optional if a variable has a pre-defined value).
• [ ] Code has been blacked for style consistency and linting.
• [ ] If applicable, version information has been updated in GANDLF/version.py.
• [ ] If adding a git submodule, add to list of exceptions for black styling in pyproject.toml file.
• [ ] Usage documentation has been updated, if appropriate.
• [ ] Tests added or modified to cover the changes; if coverage is reduced, please give explanation.
• [ ] If customized dependency installation is required (i.e., a separate pip install step is needed for PR to be functional), please ensure it is reflected in all the files that control the CI, namely: python-test.yml, and all docker files [1,2,3].
• [ ] The logging library is being used and no print statements are left.

[github-actions[bot]]

MLCommons CLA bot All contributors have signed the MLCommons CLA ✍️ ✅

[codecov[bot]]

Codecov Report

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

Project coverage is 94.59%. Comparing base (2953a5e) to head (0815fc8).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #950 +/- ## ========================================== + Coverage 94.58% 94.59% +0.01% ========================================== Files 161 161 Lines 9567 9567 ========================================== + Hits 9049 9050 +1 + Misses 518 517 -1 ``` | [Flag](https://app.codecov.io/gh/mlcommons/GaNDLF/pull/950/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=mlcommons) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/mlcommons/GaNDLF/pull/950/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=mlcommons) | `94.59% <ø> (+0.01%)` | :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=mlcommons#carryforward-flags-in-the-pull-request-comment) to find out more.

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