Upgrade GSL Library to v2.7.1

GSL library is updated to v2.7.1 via vcpkg: gsl:x64-windows. Therefore the test can be executed.

Resolves issues #21 (closed) #660 (closed) #160 (closed)

Tests/Examples/CMakeLists.txt

@@ -146,9 +146,7 @@ test_example(scatter2d/HexagonalLatticesWithBasis 2e-10)
 test_example(scatter2d/Interference1DLattice 1.5)
 test_example(scatter2d/Interference1DRadialParacrystal 2e-10)
 test_example(scatter2d/Interference2DCenteredSquareLattice 2e-10)
-if(NOT WIN32) # https://jugit.fz-juelich.de/mlz/bornagain/-/issues/21
-    test_example(scatter2d/Interference2DParacrystal 2e-10)
-endif()
+test_example(scatter2d/Interference2DParacrystal 2e-10)
 test_example(scatter2d/Interference2DRotatedSquareLattice 2e-10)
 test_example(scatter2d/Interference2DSquareFiniteLattice 2e-10)
 test_example(scatter2d/LatticeOrientationDistribution 2e-10)