GT_CACHE_DIR_NAME is not honored

[FlorianDeconinck]

Due to nature of the restrictive compilation for both orchestrated and non-orchestrated backends (e.g. compile of N ranks run on M) generating the path to the cache following GT_CACHE_DIR_NAME will lead to issues.
Mainly we need GT4Py, DaCe and pieces of Pace to all agree, while there is more than one entry to the code base.

Pending a fix coming, the GT_CACHE_ROOT works and the directory is always called .gt_cache_XXXXXX.

GT_CACHE_DIR_NAME issue cannot be solved easily without going back to GT4Py.