fix linking with LDLIBS instead of CFLAGS

[wardviaene]

Related to #84

The downloaded asset sqlite-vec-0.1.6-loadable-linux-x86_64.tar.gz has this output from ldd:

	linux-vdso.so.1 (0x00007ffff81f4000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x000079df72200000)
	/lib64/ld-linux-x86-64.so.2 (0x000079df724b5000)

The -lm flag needs to be moved to the end. After the change, the ldd output is:

	linux-vdso.so.1 (0x00007ffcfbf8d000)
	libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x0000706bf3b42000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x0000706bf3800000)
	/lib64/ld-linux-x86-64.so.2 (0x0000706bf3c56000)

Fixing the dependency on libm, and removing any undefined symbol: sqrtf errors when downloading the shared library file