Eliminate calls to flattenSingleValue() that are no longer required when we're checking for array values as arguments (#2591)

src/PhpSpreadsheet/Calculation/MathTrig/Arabic.php

@@ -86,7 +86,7 @@ class Arabic
         }
 
         // An empty string should return 0
-        $roman = substr(trim(strtoupper((string) Functions::flattenSingleValue($roman))), 0, 255);
+        $roman = substr(trim(strtoupper((string) $roman)), 0, 255);
         if ($roman === '') {
             return 0;
         }

src/PhpSpreadsheet/Calculation/MathTrig/Base.php

@@ -41,7 +41,6 @@ class Base
         } catch (Exception $e) {
             return $e->getMessage();
         }
-        $minLength = Functions::flattenSingleValue($minLength);
 
         return self::calculate($number, $radix, $minLength);
     }