[Disable] Skip running llbuild test until issue is resolved swiftlang/swift-llbuild#894

(cherry picked from commit 5bc7c39)

Author: shahmishal

utils/build-presets.ini

@@ -1687,6 +1687,10 @@ sil-verify-all-macos-only
 skip-test-ios-host
 skip-test-watchos-host
 
+# Skip LLBuild test until GitHub issue is fixed:
+# https://github.com/apple/swift-llbuild/issues/894
+skip-test-llbuild
+
 [preset: llvm_project_pull_request]
 mixin-preset=buildbot_all_platforms,tools=RA,stdlib=RA