fix: Fix to_string error

[nikitosing]

Motivation

(ArgumentError) cannot convert the given list to a string.

Changelog

• to_string -> inspect

Checklist for your Pull Request (PR)

• If I added new functionality, I added tests covering it.
• If I fixed a bug, I added a regression test to prevent the bug from silently reappearing again.
• I checked whether I should update the docs and did so by submitting a PR to https://github.com/blockscout/docs
• If I added/changed/removed ENV var, I submitted a PR to https://github.com/blockscout/docs to update the list of env vars at https://github.com/blockscout/docs/blob/master/for-developers/information-and-settings/env-variables.md and I updated the version to master in the Version column. Changes will be reflected in this table: https://docs.blockscout.com/for-developers/information-and-settings/env-variables.
• If I added new DB indices, I checked, that they are not redundant with PGHero or other tools.
• If I added/removed chain type, I modified the Github CI matrix and PR labels accordingly.