codecov has stopped working

[cjrace]

Describe the bug

We used to have codecov regularly reported, though the connection from the GitHub actions seems to have broken around a month ago.

How to reproduce

Either:

1. Go direct to https://app.codecov.io/gh/dfe-analytical-services and look at the last updated date.

2. Look at a recent GitHub action run and see that while it tracks the %'s it isn't uploading them to codecov anymore.

Example - https://github.com/dfe-analytical-services/dfeshiny/actions/runs/11121918631/job/30902072471.

Expected behaviour

Should be updated on at least every push to main, usually on pushes to branches too.

Screenshots

Additional context

It says rate limit exceeded, though as far as I was aware we were on a free plan and weren't close to the limit so seems odd that we've suddenly exceeded it.