nss_esr: backport gcc-13 fix

[trofi]

Without the change nss build on gcc-13 fails as:

../../cpputil/databuffer.h:20:20: error: 'uint8_t' does not name a type
   20 |   DataBuffer(const uint8_t* d, size_t l) : data_(nullptr), len_(0) {
      |                    ^~~~~~~
../../cpputil/databuffer.h:14:1: note: 'uint8_t' is defined in header '<cstdint>'; did you forget to '#include <cstdint>'?
   13 | #include <iostream>
  +++ |+#include <cstdint>
   14 |

Description of changes

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 23.05 Release Notes (or backporting 22.11 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.