Fix CI (#1316)

* Fix deterministic WASM check

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Fix build-staking-miner

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Remove Kusama and Polkadot runtime-migration checks

Will be removed in https://github.com/paritytech/polkadot-sdk/pull/1304 anyway.

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

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Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>