fix: ignore account txn query for unsupported networks [APE-801]

[antazoey]

What I did

ignore unsupported networks by returning None for query estimation thanks @fubuloubu for telling me how to start this

How I did it

How to verify it

Checklist

• [ ] Passes all linting checks (pre-commit and CI jobs)
• [ ] New test cases have been added and are passing
• [ ] Documentation has been updated
• [ ] PR title follows Conventional Commit standard (will be automatically included in the changelog)

[linear[bot]]

APE-801 "fix: ignore account txn query for unsupported networks" (ApeWorX/ape-etherscan #83)

### What I did ignore unsupported networks by returning None for query estimation thanks fubuloubu for telling me how to start this ### How I did it ### How to verify it ### Checklist * [ ] Passes all linting checks (pre-commit and CI jobs) * [ ] New test cases have been added and are passing * [ ] Documentation has been updated * [ ] PR title follows [Conventional Commit](https://www.conventionalcommits.org/en/v1.0.0/) standard (will be automatically included in the changelog) --- [ApeWorX/ape-etherscan #83](https://github.com/ApeWorX/ape-etherscan/pull/83) by [unparalleled-js](https://github.com/unparalleled-js) on GitHub *via LinearSync*