feat: Add swift wasm CI targets to DataLoader

[scottmarchant]

Change summary

Added swift wasm as a CI target, to help prevent future breakages to swift wasm builds in DataLoader

Details

• Added ci stage that checks wasm compilation.
• Temporarily pointing to a branch of swift-nio to verify wasm compilation, as swift-nio/NIOCore is currently broken. The swift-nio version will be bumped before merging this.
• Bump swift version from 5.8 to 5.10.0, which is the new minimum for the latest swift-nio dependency.
• Add wasi 0.1 build status badge to README.md.

Notes

• Because the build status badge uses an unmerged workflow (.github/workflows/wasm.yaml), it can't be tested until this PR is merged. Some follow-on work may be needed after merging to ensure proper badge functionality.
• This PR is part of a larger effort by PassiveLogic to add wasm support to many popular repositories.

PR Dependencies

The following PR's must be merged before this PR can be merged:

• https://github.com/GraphQLSwift/ci/pull/3
• https://github.com/apple/swift-nio/pull/3271

Testing done

Verified new github workflow builds, once required upstream dependencies are patched in swift-nio

See https://github.com/PassiveLogic/DataLoader/actions/runs/15833601501/job/44631947127?pr=1

Remaining work

• [x] Update this PR after swift-nio wasm build is merged and released
• [ ] After merging, verify badge works as expected. As noted, this can't be tested until after merging. Submit patch for new badge if needed.