FirstRun: add missing libsecret dep for Alpine

This allows building qtkeychain which is a dep for NeoChat
2 jobs for alpine-firstrun-libsecret in 2 minutes and 30 seconds (queued for 88 minutes and 4 seconds)
Status Job ID Name Coverage
  Test
passed #93613
smoke-test

00:01:55

passed #93612
unit-test

00:00:34