Misc fixes for 8.0 (testing, plugins, gitdm) - update Alpine image used for testing images - include libslirp in custom runner build env - update gitlab-runner recipe for CentOS - update docker calls for better caching behaviour - document some plugin callbacks - don't use tags to define drives for lkft baseline tests - fix missing clear of plugin_mem_cbs - fix iotests to report individual results - update the gitdm metadata for contributors - temporally disable gdb registers for pauth - avoid printing comments before g_test_init()