The out-dated version (bad tag) of [polkadot
image](https://github.com/paritytech/polkadot-sdk/blob/ede4a362

/.gitlab/pipeline/zombienet/cumulus.yml#L31)
([docker
info](https://hub.docker.com/layers/paritypr/polkadot-debug/master/images/sha256:adb1658052cf671b50c90d5cece5c7a131efa1a95978249bd5cb85a5ad654f7a?context=explore))
was used. This PR fixes this.

See also:
https://github.com/paritytech/polkadot-sdk/pull/2411#issuecomment-1822632724

Also adds an abstraction that allows asynchronous backends to be passed to `ChainApiSubsystem`
---------

Co-authored-by: Sebastian Kunert <[email protected]>