slapos_jio*: Drop unused instance and code

  it cause confusion on grep and search, if we need access its code,
  we may rely on https://lab.nexedi.com/nexedi/slapos.core/-/tree/master/master/bt5/slapos_jio
2 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
passed SlapOS-Master.UnitTest-Rafael

01:58:50

failed SlapOS-Master.UnitTest-Rafael

01:49:31