sagemathgh-40126: Simplify QuiverRep_generic.linear_combination_of_basis method
    
Shorten the code.

This might become faster after
sagemath#39726 (or might not, I haven't
benchmarked)

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URL: sagemath#40126
Reported by: user202729
Reviewer(s): Travis Scrimshaw

Author: Release Manager

src/sage/quivers/representation.py

@@ -2013,11 +2013,7 @@ def linear_combination_of_basis(self, coordinates):
         gens = self.gens()
         if len(gens) != len(coordinates):
             raise ValueError("the coordinates do not match the dimension of the module")
-
-        result = self()  # this must not be self.zero(), which is cached
-        for ci, gi in zip(coordinates, gens):
-            result += ci * gi
-        return result
+        return self.sum(ci * gi for ci, gi in zip(coordinates, gens))
 
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