Without the change the build fails on `master` as
https://hydra.nixos.org/build/246448950:
In file included from /build/rippled/src/test/basics/base64_test.cpp:29,
from /build/rippled/build/CMakeFiles/rippled.dir/Unity/unity_23_cxx.cxx:4:
/build/rippled/src/ripple/basics/base64.h:65:20: error: 'uint8_t' is not a member of 'std'; did you mean 'wint_t'?
65 | base64_encode(std::uint8_t const* data, std::size_t len);
| ^~~~~~~
| wint_t
a799f841be