'warn' parameter not used in write_part() routine

[MichaelChirico]

terra/src/raster_methods.cpp

Line 3470 in 001bdfb

bool write_part(SpatRaster& out, SpatRaster& r, const double& hxr, size_t& nl, bool notfirstlyr, bool warn, SpatOptions &opt) {

This is flagged by clang's -Wunused-but-set-parameter. Reading the implementation the warning looks good -- the routine takes warn as an input but doesn't use it.

Should a warning be thrown somewhere if it winds up true? Or perhaps it should be dropped.

I'm happy to file a PR but lack context on what's the right fix.

[rhijmans]

Fixed with ac993dd