core: Use `TriesInMemory` from config

[ngotchac]

Description

The config setting got mistakenly removed in this PR https://github.com/maticnetwork/bor/pull/1300/files

Without those changes, we cannot set TriesInMemory to anything but the default value.

Changes

• [x] Bugfix (non-breaking change that solves an issue)
• [ ] Hotfix (change that solves an urgent issue, and requires immediate attention)
• [ ] New feature (non-breaking change that adds functionality)
• [ ] Breaking change (change that is not backwards-compatible and/or changes current functionality)
• [ ] Changes only for a subset of nodes

Checklist

• [ ] I have added at least 2 reviewer or the whole pos-v1 team
• [ ] I have added sufficient documentation in code
• [ ] I will be resolving comments - if any - by pushing each fix in a separate commit and linking the commit hash in the comment reply
• [ ] Created a task in Jira and informed the team for implementation in Erigon client (if applicable)
• [ ] Includes RPC methods changes, and the Notion documentation has been updated

Cross repository changes

• [ ] This PR requires changes to heimdall
  • In case link the PR here:
• [ ] This PR requires changes to matic-cli
  • In case link the PR here:

Testing

• [ ] I have added unit tests
• [ ] I have added tests to CI
• [ ] I have tested this code manually on local environment
• [ ] I have tested this code manually on remote devnet using express-cli
• [ ] I have tested this code manually on amoy
• [ ] I have created new e2e tests into express-cli

Manual tests

Please complete this section with the steps you performed if you ran manual tests for this functionality, otherwise delete it