[CI] Update to Swift 6 CI

[FranzBusch]

Motivation

We just updated our CI matrix in NIO to only support 5.9, 5.10 and 6.

Modification

This PR updates the trigger files in this repo. Since this repo was always 5.9+ this is easy.

Result

Up to date CI

[czechboy0]

@FranzBusch

[Invalid workflow file: .github/workflows/pull_request.yml#L10](https://github.com/apple/swift-openapi-runtime/actions/runs/11345355766/workflow)
error parsing called workflow
".github/workflows/pull_request.yml"
-> "apple/swift-nio/.github/workflows/soundness.yml@main"
: failed to fetch workflow: workflow was not found.

[czechboy0]

Should this be switched to the reusable one?

[czechboy0]

Same here? https://github.com/apple/swift-openapi-runtime/pull/122/files#r1801118837

[FranzBusch]

Updated the other one but this one is correct

[FranzBusch]

@czechboy0 @simonjbeaumont the documentation pipeline seems to be failing since switching over to the reusable repo updated the toolchain for that workflow from 5.10 to 6.0. It looks like there are some new warnings now that need to be fixed. Could you help me with that?

[czechboy0]

@czechboy0 @simonjbeaumont the documentation pipeline seems to be failing since switching over to the reusable repo updated the toolchain for that workflow from 5.10 to 6.0. It looks like there are some new warnings now that need to be fixed. Could you help me with that?

Yes let me open a separate PR making those fixes first.

[czechboy0]

@FranzBusch #123

[czechboy0]

@FranzBusch Actually, we have a chicken-and-egg problem, you need to bring this tiny diff into your PR instead, I can't merge mine with green CI anyway: #123

[FranzBusch]

@czechboy0 Thanks for that. I slightly tweaked your commit to also avoid the Return: on the closure since that documents the wrong thing. I am wondering if that should actually be allowed.

[czechboy0]

@FranzBusch So the YAML linter still fails: PR / Soundness / YAML lint check (pull_request)

[FranzBusch]

@czechboy0 fixed!

[czechboy0]

@czechboy0 fixed!

I still see it as failing 😬

[FranzBusch]

@czechboy0 Finally it's all green. Please do me the honours!