chore: bump subxt version to 0.37.0

[AlexD10S]

This PR upgrades the subxt and subxt-signer library from version 0.35.3 to 0.37.0.
This upgrade is necessary because version 0.37 of subxt includes support for the signed extension CheckMetadataHash.

This solves an issue when uploading a smart contract on certain chains.
How to Replicate the Issue:

// Generate a contracts parachain
pop new parachain contracts-parachain --template contracts
cd contracts-parachain
// Run it
pop up parachain -f ./network.toml
// Generate a new smart contract
cd .. & pop new contract
// Try to upload it
cargo contract upload --suri //Alice --url ws://127.0.0.1:57869 -x

This will throw the error:

ERROR: Extrinsic params error: The chain expects a signed extension with the name CheckMetadataHash, but we did not provide one

This issue is resolved with this upgrade.