ci: bump to LLVM 16

.github/workflows/main.yml

@@ -31,15 +31,15 @@ jobs:
     # Prevent Clang from using DWARF5, not supported by the valgrind version in runners
     - name: Set environment for Clang
       run: |
-        echo "CC=clang-15" >> $GITHUB_ENV
+        echo "CC=clang-16" >> $GITHUB_ENV
         echo "CFLAGS=-gdwarf-4 -O2" >> $GITHUB_ENV
       if: ${{ matrix.cc == 'clang' }}
     - name: install clang repo
       run: |
         wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key 2>/dev/null | sudo apt-key add -
-        sudo add-apt-repository 'deb http://apt.llvm.org/focal/ llvm-toolchain-focal-15 main' -y
+        sudo add-apt-repository 'deb http://apt.llvm.org/focal/ llvm-toolchain-focal-16 main' -y
         sudo apt-get update -q
-        sudo apt-get install -y clang-15
+        sudo apt-get install -y clang-16
       if: ${{ matrix.cc == 'clang' }}
     - name: install dependencies
       run: |