Add qtkeychain to install lists

Currently translated at 100.0% (412 of 412 strings)

Co-authored-by: Priit Jõerüüt <nhkwlate@joeruut.com>
Translate-URL: https://weblate.nheko.im/projects/nheko/nheko-master/et/
Translation: Nheko/nheko

Cross-signing with self and user signing keys

Currently translated at 54.3% (224 of 412 strings)

Co-authored-by: Priit Jõerüüt <nhkwlate@joeruut.com>
Translate-URL: https://weblate.nheko.im/projects/nheko/nheko-master/fi/
Translation: Nheko/nheko

This fixes some lag, when Nheko is running, which could affect Nheko and
even other applications by excessively calling fsync. This should be
fine, since all filesystems seem to guarantee order and in most cases,
the modified pages are still written. In the worst case we should only
lose the last /sync results or similar.

lint

Update .gitlab-ci.yml

See merge request !1

Use system icon where applicable

update russian translate

Add GStreamer requirements to README