Fix false positives for unused_enumerated with result member access

[theamodhshetty]

Summary

• avoid flagging .enumerated() when a higher-order call uses tuple members like ?.offset after the closure
• keep tracking $0.element / $0.0 and seed the closure usage from result-member access on the surrounding call
• add regression examples and the required changelog entry

Testing

• swift test --filter UnusedEnumeratedRuleGeneratedTests
• ./.build/debug/swiftlint lint Source/SwiftLintBuiltInRules/Rules/Idiomatic/UnusedEnumeratedRule.swift CHANGELOG.md --strict
• ./.build/debug/swiftlint lint --only-rule unused_enumerated /tmp/unused_enumerated_ok.swift --quiet
• ./.build/debug/swiftlint lint --only-rule unused_enumerated /tmp/unused_enumerated_bad.swift --quiet

Closes #5881

[SwiftLintBot]

	1 Warning
⚠️	This PR may need tests.

	19 Messages
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[theamodhshetty]

Pushed a small follow-up in eb3575a after the first CI pass.

The original version reset nextClosureId / lastEnumeratedPosition inside the same if let that introduced shorthand bindings with those names, which newer matrix legs were treating as the shadowed locals instead of the stored properties. This update just renames the local bindings so the property resets stay unambiguous across toolchains.