A0-3755: Faucet cleaup

[Marcin-Radecki]

This PR is required work before fixing bug in which RPC node gets restarted, and faucet remains in an undefined state and only restart helps. So in this PR we

• bump polkadot-js lib and all its deps (as per upstream) to see if this problem is gone. Btw issue is not reproducible locally, but only on our infra, so we need to have some officially built version from alephzero branch
• remove all not required deployment files
• update ES lint settings (thus they are more restrictive now)
• update dockerfile to be on Node 20
• update worfklows to have basics:
  • linter, build on PR
  • build and push to ECR on alephzero commit
  • deploy to Testnet on demand
  • yaml linter and validator on PR
• removed entirely Bot functionality, which we don't use anyway
• support for balances.transfer removal from runtime (change backwards compatible)

Testing: tested changes locally (sending token works)

Post-merge steps:

• make main default branch: this requires merging alephzero to main branches and then changing repo settings. We won't update from upstream most likely as this app is very simple now and pretty much won't be changed a lot.
• change repo name to azero-faucet, as there's no Matrix functionality anymore in it

[Kosiare]

LGTM (checked only workflow and related changes)