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.

Note
In addition to bumping the subxt version, some other changes were made:

• Remove the file metadata_v11.scale and its test. The test was failing here. Based on what I read in an issue opened in the subxt repo link, it seems the only way to fix it is to regenerated the metadata files used in the tests after the upgrade.
  However, using the latest subxt-cli to regenerate the file for V11 was showing an error:

The node can only return version 14 metadata using the legacy API, but you've requested a different version.

The reason for this error is that subxt doesn't support anything before V14. Since cargo-contract relies heavily on subxt, the best approach seems to be supporting only from V14 onwards.

• The CI was failing during the clippy checks, so I had to add some code to fix that. To make it easier for the reviewer, all changes related to this issue can be seen in this commit: 37cfd93