ci: Fix the linux-x86 job

Now that ubuntu-latest refers to a newer Ubuntu release, we need to
move to the newer lib32stdc++ package version that matches that of
the gcc-multilib package.

.github/workflows/ci.yml

@@ -44,7 +44,7 @@ jobs:
         if: matrix.id == 'linux-x86'
         run: |
           sudo apt-get update
-          sudo apt-get install gcc-multilib lib32stdc++-11-dev
+          sudo apt-get install gcc-multilib lib32stdc++-13-dev
       - name: Build
         if: ${{ startsWith(matrix.id, 'windows-') }}
         run: |