test(api): remove accountsHashDifficulty test suite

[saw-jan]

Description

There is no accounts service which makes the use of ACCOUNTS_HASH_DIFFICULTY obsolete. Therefore, running separate test suite with ACCOUNTS_HASH_DIFFICULTY is no longer valid, it will just be a duplication.

Related Issue

Motivation and Context

How Has This Been Tested?

• test environment:

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Technical debt
• Tests only (no source changes)

Checklist:

• Code changes
• Unit tests added
• Acceptance tests added
• Documentation added