hotfix/memory-aerosol

In the aerosol code, each asynchronous communication of a vector through pampa produced a memory leak that was causing memory issues for a large enough number of iterations. The asynchronous communication was performed through the sequence:

PAMPA_DmeshHaloReqs
PAMPA_dmeshHaloTagAsync
PAMPA_dmeshHaloWait

With @vperrier, we verified that the problem came from the entttab pointer never deallocated within this sequence. The proposed fix avoids the memory leak and should not affect any functionality in the asynchronous communication.

Thanks @fpellegr to have a look at this merge request.