ci(codecov): disable CodeCov

[kisvegabor]

Description of the feature or fix

We don't use it and the upload fails quite often.

Notes

• Update the Documentation if needed.
• Add Examples if relevant.
• Add Tests if applicable.
• If you added new options to lv_conf_template.h run lv_conf_internal_gen.py and update Kconfig.
• Run scripts/code-format.py (astyle needs to be installed) and follow the Code Conventions
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• When changes were requested, re-request review to notify the maintainers.
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[PGNetHun]

Hurrah!
It is really unreliable service.

[PGNetHun]

Although it seems it requires a token:

Maybe worth to check this works:
https://about.codecov.io/blog/january-product-update-updating-the-codecov-ci-uploaders-to-the-codecov-cli/

[kisvegabor]

We don't use it at this moment, so I would rather disable it.