Monitoring tool codecov

[6543]

Discussion:

• remove code coverage monitoring at all
• find a solution that works on gitea.com too

-> #18443 (comment)
-> #18443 (review)

[6543]

cc @go-gitea/maintainers

[wxiaoguang]

I am fine with either keeping (not bad) or removing (no help, maybe no one really looks into it)

[delvh]

I am in favor of removing it entirely for the following reasons:
a) I dislike that on every single PR, such a comment will be generated. This makes scrolling in a PR a pain, especially for small PRs simply because of the comment size. (It is larger than a screen is high)
b) I don't understand its algorithm/ information. I have seen coverage changes in PRs that were only adjusting the documentation. Why would the coverage differ in such a case? That seems counter-intuitive to me explained by @zeripath, see below
c) I have never looked at it at all, despite being present in every PR. Partially because of the reasons mentioned above.

[zeripath]

The coverage is slightly different each time the test-suite is run due to the inherent non-determinism in the integration test cases.

The problem is that no-one (including myself) is looking at the coverage or trying to actively increase it or work on preventing coverage getting lower.

[6543]

I personally find the report on pulls useless but tho monitor the trend important...