doc: fix missing kwarg in qt5 module
compile_moc accepts "dependencies" for the same reason preprocess does,
but the original documentation never copied this over from the
preprocess docs.
See:
@@ -46,6 +46,7 @@ It takes no positional arguments, and the following keyword arguments:
- `extra_args` string[]: Extra arguments to pass directly to `qt-moc`
- `method` string: The method to use to detect qt, see `dependency()` for more
information.
+ - `dependencies`: dependency objects whose include directories are used by moc.
- `include_directories` (string | IncludeDirectory)[]: A list of `include_directory()`
objects used when transpiling the .moc files
