Since commit deabd4a, psl2c has been replaced by psl-make-dafsa.
The builtin PSL data is always generated the same way, and the value of the builtin
configure option does not matter anymore.
The built-in data is now embedded by default (instead of the previous "auto"), unless
explicitly disabled by --disable-builtin/-Dbuiltin=false.
When not using an run-time runtime IDNA library (--disable-runtime/-Druntime=no), libpsl can
now include the built-in data without any build-time dependency.
We must link to ws2_32.lib for all Windows builds, and we need to use
workarounds for alloca() and snprintf() since Visual Studio uses
_alloca() for alloca() and provides snprintf() only on Visual Studio
2015 or later, meaning that we need to use _snprintf() here.
Also fix the parts where we run the Python scripts to generate items,
since those scripts already have shebang lines for Meson to pick up.