This PR makes possible to build the qt package in depends against libc++ for x86_64 platform.
Fixes #22344.
Required for #22815.
Also this PR fixes the [no wallet] [bionic] task on CI:
- on master (a8bbd4cc819633ec50ed0f763b6a75330ae055fb), https://api.cirrus-ci.com/v1/task/5558609250615296/logs/ci.log:
Options used to compile and link:
external signer = yes
multiprocess = no
with libs = yes
with wallet = no
with gui / qt = no
Options used to compile and link:
external signer = yes
multiprocess = no
with libs = yes
with wallet = no
with gui / qt = yes