[backport] qa: Make tmpdir option an absolute path, misc cleanup
Summary:
Backport of Core PR11472:
fafa003 qa: Remove never used return value of sync_with_ping (MarcoFalke) fa9de37 qa: Make tmpdir option an absolute path (MarcoFalke)
Pull request description:
This should fix issues with the multiwallet test and its symlinks when the tmpdir is a relative path. Rather than fixing os.symlink to work with paths relative to a directory descriptor, which does not work on Windows, normalize the path instead.
Test Plan: ./test/functional/test_runner.py
Reviewers: matiu, deadalnix, #bitcoin_abc
Reviewed By: matiu, #bitcoin_abc
Subscribers: teamcity
Differential Revision: https://reviews.bitcoinabc.org/D1053