fix(ci): allow blacksmith 16vcpu labels in actionlint

.github/actionlint.yaml

@@ -1,17 +1,6 @@
-# actionlint configuration
-# https://github.com/rhysd/actionlint/blob/main/docs/config.md
-
-self-hosted-runner:
-  labels:
-    # Blacksmith CI runners
-    - blacksmith-8vcpu-ubuntu-2404
-    - blacksmith-8vcpu-windows-2025
-
-# Ignore patterns for known issues
 paths:
-  .github/workflows/**/*.yml:
+  .github/workflows/**/*.{yml,yaml}:
     ignore:
-      # Ignore shellcheck warnings (we run shellcheck separately)
-      - "shellcheck reported issue.+"
-      # Ignore intentional if: false for disabled jobs
-      - 'constant expression "false" in condition'
+      # actionlint's built-in runner label allowlist lags Blacksmith additions.
+      # Keep runner validation enabled otherwise, but suppress this known false-positive.
+      - 'label "blacksmith-16vcpu-[^"]+" is unknown\.'