Boost build error on Clang CI builds

https://github.com/offa/influxdb-cxx/actions/runs/9649760339/job/26613913397

```
 In file included from /usr/lib/llvm-18/bin/../include/c++/v1/__assertion_handler:13:
/usr/lib/llvm-18/bin/../include/c++/v1/__config:13:10: fatal error: '__config_site' file not found
   13 | #include <__config_site>
      |          ^~~~~~~~~~~~~~~
1 error generated.
```