Updated the wrong workflow

Author: adam-yang

.github/workflows/llvm-project-tests.yml

@@ -95,7 +95,7 @@ jobs:
         with:
           fetch-depth: 250
       - name: Setup ccache
-        uses: hendrikmuhs/ccache-action@v1
+        uses: hendrikmuhs/ccache-action@ed74d11c0b343532753ecead8a951bb09bb34bc9 # v1.2
         with:
           # A full build of llvm, clang, lld, and lldb takes about 250MB
           # of ccache space. There's not much reason to have more than this,