fix(bsppp): add algorithm to fix missing sort

[HurricanePootis]

src/bsppp/bsppp.cpp is missing an #include <algorithm>

Compiling vpkedit head results in this error without it:

/home/hurricane/aur/vpkedit-git/src/vpkedit-git/src/shared/thirdparty/sourcepp/src/bsppp/bsppp.cpp:178:8: error: no member named 'sort' in namespace 'std'
  178 |                 std::sort(lumpIDs.begin(), lumpIDs.end(), [this](int lhs, int rhs) {
      |                 ~~~~~^
1 error generated.

[craftablescience]

It's always algorithm