Resolve "Add NC calendar app"

Closes nextcloud#973 and #905

See merge request openappstack/openappstack!467

Weirdly, going directly from Calendar to Files fails, taiko displays
no files. So we need to take an extra roundtrip via the Dashboard *sigh*

See https://open.greenhost.net/openappstack/openappstack/-/jobs/107990

Closes: #905

Resolve "Loki gets oom killed"

Closes #840 and #911

See merge request openappstack/openappstack!471

Closes: #840

Related: #910

Update and configure loki

See merge request openappstack/openappstack!469

Resolve "Update to NC 20"

Closes #899

See merge request openappstack/openappstack!464

Resolve "Onlyoffice taiko test should catch installation error"

Closes #897

See merge request openappstack/openappstack!462

Fixes: #897

Resolve "Follow Greenhost cloud API change to droplet status values"

Closes #902

See merge request openappstack/openappstack!466

Allow Rocket.Chat test to fail

Closes #857

See merge request openappstack/openappstack!461

Closes: #857

Resolve "Add wekan as project management tool"

Closes #813, #820, and #878

See merge request openappstack/openappstack!458