* ci: remove build-check job from CI workflow
The cross-platform build verification is redundant in CI since the
build and release pipeline (build.yml) already performs full builds
on every release. This reduces CI runner time and costs.
* ci: restrict build-check to Linux PRs and pin R2 action to v1.4
- Build-check now only runs on pull requests (skipped on main merge)
with only Linux/amd64 enabled; macOS and Windows are commented out
since the Build & Publish workflow handles all platforms on release.
- Pin ryand56/r2-upload-action from floating v1 tag to v1.4 to fix
the upload failure seen in the v1.1.0 release build.
logan
42d3f45d85