Fix CI and spec versions

[FabijanC]

• Fixes the CI
  • It was silently failing (check the step Run npm run validate_all).
• Unifies references to starknet_api_openrpc.json:
  • There were both ./api/starknet_api_openrpc.json and ./starknet_api_openrpc.json references; changed it to only use the former
  • In fact, validation was failing because of invalid refererences
• Addresses the TODO in validate.js
  • No longer dependent on the cwd (e.g. works in both project root and in api/)
• Closes #181
  • As suggested in the issue I am using the package.json version as the source of truth.
  • This is open for discussion. I can change the name in package.json to maybe reflect the whole repository, not just the validation tooling (e.g. "name": "starknet_specs" instead of "name": "openrpc_scripts").
  • Alternatively, another source of truth can be used (e.g. env var or env file)
  • Changed "name": "openrpc_scripts" to "name": "starknet_specs" so that it reflects the whole repository, not just the validation tooling

Now that validation has been fixed, when running it locally, a validation error is reported in api/starknet_trace_api_openrpc.json:

[
  {
    "keyword": "additionalProperties",
    "dataPath": ".components.errors['TXN_HASH_NOT_FOUND']",
    "schemaPath": "#/additionalProperties",
    "params": {
      "additionalProperty": "$ref"
    },
    "message": "should NOT have additional properties"
  }
]

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This change is