Address limitations of using nf-test sharding

[edmundmiller]

List post #6286 that aren't breaking but would be nice to have

### Tasks
- [ ] Functioning Test Report
- [ ] Smart number of shards
- [ ] Avoid failing conda tests
- [ ] Add branch checks for CI jobs

[edmundmiller]

On the conda failures, I see a few options going from short-term/making more maintence work to long-term

1. Implement some "exclude" type of mechanism in GitHub actions
2. Tag all of the tests that work with conda with a "conda" tag and we select for those using a --tag conda_works tag in the conda matrix profile
3. Address it at the root with working on In-verse tag selection askimed/nf-test#260

We could skip the conda tests in 3 until we get that implemented. Not the end of the world IMO given the conda headaches, but I'm biased.