Basics: fix `DiagnosticsHanderWrapper` typo (#5877)
Basics: fix `DiagnosticsHanderWrapper` typo (#5877)

Applied renaming to `DiagnosticsHandlerWrapper` within `Basics/Observability.swift`.
abertelrud/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager