change try-runtime rpc domains (#5443)

as part of paritytech/devops/3502, try-runtime nodes were migrated to a
new provider with a new domain address. The PR fixes all the references
to try-runtime nodes on rococo, westend, kusama and polkadot networks.

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Co-authored-by: ArshamTeymouri <ArshamTeymouri@users.noreply.github.com>
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: Niklas Adolfsson <niklasadolfsson1@gmail.com>