GitHub keywords to close any associated issues

Motivation

Why we should merge these changes. If using GitHub keywords to close issues, this is optional as the motivation can be read on the issue page.

Changelog

Enhancements

Things you added that don't break anything. Regression tests for Bug Fixes count as Enhancements.

Bug Fixes

Things you changed that fix bugs. If a fixes a bug, but in so doing adds a new requirement, removes code, or requires a database reset and reindex, the breaking part of the change should be added to Incompatible Changes below also.

Incompatible Changes

Things you broke while doing Enhancements and Bug Fixes. Breaking changes include (1) adding new requirements and (2) removing code. Renaming counts as (2) because a rename is a removal followed by an add.

Upgrading

If you have any Incompatible Changes in the above Changelog, outline how users of prior versions can upgrade once this PR lands or when reviewers are testing locally. A common upgrading step is "Database reset and re-index required".

Checklist for your Pull Request (PR)

• I added an entry to CHANGELOG.md with this 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 add new indices into DB, I checked, that they are not redundant with PGHero or other tools