chore: fix libzstd spec source URL

in playing around w/ package and package sources in bottlerocket, I
noticed some 404s. Some were due to the issue outlined in bottlerocket-os#2831
regarding GitHubs switch away from generated archives, with this typo
being an easy outlier to quickly fix.

Signed-off-by: Gavin Inglis <giinglis@amazon.com>

packages/libzstd/libzstd.spec

@@ -4,7 +4,7 @@ Release: 1%{?dist}
 Summary: Library for Zstandard compression
 License: BSD-3-Clause AND GPL-2.0-only
 URL: https://github.com/facebook/zstd/
-Source0: https://github.com/faceboot/zstd/releases/download/v%{version}/zstd-%{version}.tar.gz
+Source0: https://github.com/facebook/zstd/releases/download/v%{version}/zstd-%{version}.tar.gz
 BuildRequires: %{_cross_os}glibc-devel
 
 %description