Pipeline download resulting images have stringent permissions after refactoring #3730
Description
NOTE: Issue introduced by #3634
Images are created with permissions rw------- (and it's not a umask thing from my environment).
$ ls -l fngs/singularity-images/ | grep -v '^l'
total 523852
-rw------- 1 mm49 team328 154169344 Aug 16 14:32 mulled-v2-5f89fe0cd045cb1d615630b9261a1d17943a9b6a-2f4a4c900edd6801ff0068c2b3048b4459d119eb-0.img
-rw------- 1 mm49 team328 62779423 Aug 16 14:32 python-3.9--1.img
-rw------- 1 mm49 team328 137523200 Aug 16 14:32 sra-tools-2.11.0--pl5321ha49a11a_3.img
-rw------- 1 mm49 team328 154169344 Aug 16 14:32 sra-tools-3.0.8--h9f5acd7_0.img
-rw------- 1 mm49 team328 27750400 Aug 16 14:32 ubuntu-20.04.img
$ umask
0022
$ touch test
$ ls -l test
-rw-r--r-- 1 mm49 team328 0 Aug 16 14:34 test
Originally posted by @muffato in #3634 (comment)