OnlyRule not work with custom_rules

[Ernest0-Production]

New Issue Checklist

• I've Updated SwiftLint to the latest version.
• I've searched for existing GitHub issues.

Bug Description

If you specify a custom rule in the --only-rule argument, then no violations are detected during linting. (It does scan the files though)

When linting a built-in rule, everything works correctly

$ swiftlint lint --no-cache --only-rule my_rule

Environment

• SwiftLint version 0.58.2
• Xcode version 16.2
• Installation method used mise-en-place

[SimplyDanny]

Historically, handling of custom rules has its peculiarities and we have one of these examples here. Unexpectedly, the command to run a single custom rule is like swiftlint lint --only-rule custom_rules --only-rule my_rule.