iwyu.yml: applied apt.llvm.org workaround as well [skip ci] (#5286)

Author: firewave

.github/workflows/iwyu.yml

@@ -107,6 +107,7 @@ jobs:
 
       - name: Install clang
         run: |
+          sudo apt-get purge --auto-remove llvm python3-lldb-14 llvm-14
           wget https://apt.llvm.org/llvm.sh
           chmod +x llvm.sh
           sudo ./llvm.sh 17