gh-116745: Remove all internal usage of @LIBPYTHON@ (#116746)

Replace with MODULE_LDFLAGS.

Author: tacaswell

Misc/python-config.sh.in

@@ -46,7 +46,7 @@ LIBM="@LIBM@"
 LIBC="@LIBC@"
 SYSLIBS="$LIBM $LIBC"
 ABIFLAGS="@ABIFLAGS@"
-LIBS="@LIBPYTHON@ @LIBS@ $SYSLIBS"
+LIBS="@MODULE_LDFLAGS@ @LIBS@ $SYSLIBS"
 LIBS_EMBED="-lpython${VERSION}${ABIFLAGS} @LIBS@ $SYSLIBS"
 BASECFLAGS="@BASECFLAGS@"
 LDLIBRARY="@LDLIBRARY@"

Misc/python.pc.in

@@ -9,5 +9,5 @@ Description: Build a C extension for Python
 Requires:
 Version: @VERSION@
 Libs.private: @LIBS@
-Libs: -L${libdir} @LIBPYTHON@
+Libs: -L${libdir} @MODULE_LDFLAGS@
 Cflags: -I${includedir}/python@VERSION@@ABIFLAGS@