gh-35101: scip_backend: Remove use of deprecated sage.ext.memory_allocator
    
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Fixes #34941

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URL: #35101
Reported by: Matthias Köppe
Reviewer(s): Jonathan Kliem

Author: Release Manager

src/sage/numerical/backends/scip_backend.pyx

@@ -24,10 +24,7 @@ AUTHORS:
 
 from os import sys
 from os.path import splitext
-from sage.ext.memory_allocator cimport MemoryAllocator
 from sage.numerical.mip import MIPSolverException
-from libc.float cimport DBL_MAX
-from libc.limits cimport INT_MAX
 from pyscipopt import Model