Upgrade sharedmem to 0.3.8

@ahmedk this should fix the hang we were seeing correcting /gpfs/exfel/exp/SPB/202030/p900138/raw/r0167. The notebook still throws a lot of errors for the empty sequence 2 files, but it errors and then exits rather than getting stuck. I'm just running it to test, and it appears to be behaving correctly.

See https://github.com/rainwoodman/sharedmem/issues/21 for details of how sharedmem is involved.