Can we include mishkal in the wikispeech docker package?

• Does the licence allow this? => WMSE will have to approve of this later, but we'll include mishkal for now

• Investigate how to do this... yml file: wikispeech_compose/docker/mishkal/wikispeech-with-mishkal.yml => Almost working now, but Arabic cannot be played from the workflow demo. See T180337

• Is it possible to create a separate build for Arabic and only include mishkal with this image? HB suggested. But does this really solve anything? Wikispeech tests may cause problems since Swedish and English are required to pass all tests. => Will not do this now