Ensure build scripts are compiled before execution for Xcode 15 compa…

[Hzao]

...tibility.

This commit updates the build scripts to compile PropertyListModifier.swift into executable before running. This change addresses the issue(#17) introduced in Xcode 15, where running Swift scripts directly can lead to errors due to the updated execution environment handling, which hasn't been solved by Apple yet. By compiling Swift scripts first, we ensure compatibility with Xcode 15 and later versions, while also reducing potential environmental discrepancies.

There might be a slight increase in compilation time during the build phase, approximately by a few hundred milliseconds.