Bump coverage clang version for fix to stl

Author: mmore500

Diff for: .github/workflows/CI.yml

@@ -90,6 +90,10 @@ jobs:
     name: Measure Test Coverage
     runs-on: ubuntu-22.04
     steps:
+      - name: Set up clang
+        uses: egor-tensin/setup-clang@v1
+        with:
+          version: 15
       - uses: actions/checkout@v2
         with:
           submodules: 'recursive'