6d8bd80392
Self-hosted omp-kata runners now inject a shared S3 (RustFS, in-cluster) sccache backend via pod env (SCCACHE_BUCKET/ENDPOINT/REGION + AWS creds). The Enable-sccache step branches on SCCACHE_BUCKET: when set, sccache reads the S3 config from the inherited environment; otherwise GitHub-hosted runners (macOS, ubuntu-arm) keep the GHA cache backend since they can't reach the private RustFS.