MANIFEST_FIELD_UNSUPPORTED with service_worker on MV3

[aokellermann]

Describe the problem and steps to reproduce it:

standard use of service_worker with MV3 causes MANIFEST_FIELD_UNSUPPORTED:

  "background": {
    "service_worker": "background.js"
  }

$ bin/addons-linter ../nexus-now
Validation Summary:

errors          1              
notices         0              
warnings        0              

ERRORS:

Code                         Message                                          Description                                      File            Line   Column
MANIFEST_FIELD_UNSUPPORTED   "/background/service_worker" is not supported.   "/background/service_worker" is not supported.   manifest.json             

commit to reproduce:
aokellermann/nexus-now@b24546c

I used addons-linter binary built locally from this commit (master as of creating this issue):
12ba1f4

What happened?

lint error

What did you expect to happen?

no lint error

Anything else we should know?

┆Issue is synchronized with this Jira Task

[aokellermann]

mozilla/web-ext#2532