Remove stale AbstractMessageLevel import

Author: ChrisRackauckas

lib/NonlinearSolveBase/src/NonlinearSolveBase.jl

@@ -29,7 +29,7 @@ import SciMLBase: solve, init, __init, __solve, wrap_sol, get_root_indp, isinpla
 using SciMLJacobianOperators: JacobianOperator, StatefulJacobianOperator
 using SciMLOperators: AbstractSciMLOperator, IdentityOperator
 using SciMLLogging: SciMLLogging, @SciMLMessage, @verbosity_specifier,
-                    AbstractVerbositySpecifier, AbstractVerbosityPreset, AbstractMessageLevel,
+                    AbstractVerbositySpecifier, AbstractVerbosityPreset,
                     None, Minimal, Standard, Detailed, All, Silent, InfoLevel, WarnLevel
 
 using SymbolicIndexingInterface: SymbolicIndexingInterface