Disable GDAL caching for mosaic stitching

[dpshelio]

GDAL uses caching limited to 3000 files, which can only be seen with an ultra mega super duper verbosity (i.e., -vvvv).
How does it propagate the env variable that disables the caching through dask?

[jgomezdans]

The variable name is actually GDAL_DISABLE_READDIR_ON_OPEN=TRUE