net/probes: Expect vector<byte> from cert_info

char_traits<unsigned T> is deprecated in LLVM 18, slated for removal
in LLVM 19. Having replaced the only instance of basic_sstring<unsigned>
in seastar with a vector<byte>, we need to account for that change here.

Requires redpanda-data/seastar: d96474c6a96919b4f260dbd5ba22827948c4e000

src/v/net/probes.cc

@@ -292,7 +292,8 @@ void tls_certificate_probe::loaded(
         return;
     }
 
-    auto to_tls_serial = [](const auto& b) {
+
+    auto to_tls_serial = [](const std::vector<std::byte>& b) {
         using T = tls_serial_number::type;
         T result = 0;
         const auto end = std::min(b.size(), sizeof(T));