include clang version in repo

Author: lightseba

.github/workflows/ccpp.yml

@@ -18,7 +18,7 @@ jobs:
         run: |
           source /etc/os-release
           wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key|sudo apt-key add -
-          sudo add-apt-repository "deb http://apt.llvm.org/$UBUNTU_CODENAME/ llvm-toolchain-$UBUNTU_CODENAME main"
+          sudo add-apt-repository "deb http://apt.llvm.org/$UBUNTU_CODENAME/ llvm-toolchain-$UBUNTU_CODENAME-15 main"
           sudo apt-get update
           sudo apt-get install clang-format-15