Upgraded LLVM+Clang to version 20.1.8.

Author: agarny

.github/workflows/cd.yml

@@ -46,7 +46,7 @@ jobs:
       BUILDCACHE_DEBUG: -1
       BUILDCACHE_LOG_FILE: ""
       LLVMCLANG_MAJOR_VERSION: 20
-      LLVMCLANG_VERSION: 20.1.6
+      LLVMCLANG_VERSION: 20.1.8
     steps:
       - name: Install CMake and Ninja
         uses: lukka/get-cmake@latest