toolchain: glibc: update to glibc 2.38

toolchain: glibc: update to glibc 2.38

This updates glibc to version 2.38.

Add --enable-crypt since the crypt function got disabled in 2.38, but we
still need it.
Also add the newly introduced --enable-fortify-source flag and hook it up
to the build system.

Switch to .zst archive while at it.

Signed-off-by: Kazuki H <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/14259
[ switch to .zst and fix mirror HASH ]
Signed-off-by: Christian Marangi <[email protected]>