aws-sdk-cpp: 1.4.70 -> 1.4.78

Semi-automatic update generated by https://github.com/ryantm/nixpkgs-update tools.

This update was made based on information from https://repology.org/metapackage/aws-sdk-cpp/versions.

These checks were done:

- built on NixOS

- 0 of 0 passed binary check by having a zero exit code.
- 0 of 0 passed binary check by having the new version present in output.
- found 1.4.78 with grep in /nix/store/5jxaryh2w692r3a20nijn5q7zc2xd43v-aws-sdk-cpp-1.4.78
- directory tree listing: https://gist.github.com/9e9bda76c45da3aee968472e112d51dc
- du listing: https://gist.github.com/890b235c67a7057ba2a51cd58db3c0fa