This update for libsodium fixes the following issues:

Security fixes:

- CVE-2025-15444: Cryptographic bypass via improper elliptic curve point validation (bsc#1256070).
- CVE-2025-69277: incorrect validation of elliptic curve points certain custom cryptography or untrusted data to
  crypto_core_ed25519_is_valid_point function (bsc#1255764).

Other fixes:

- Update to 1.0.21
 * The new crypto_ipcrypt_* functions implement mechanisms for securely
 encrypting and anonymizing IP addresses.
 * The sodium_bin2ip and sodium_ip2bin helper functions have been added to
 complement the crypto_ipcrypt_* functions and easily convert addresses
 between bytes and strings.
 * XOF: the crypto_xof_shake* and crypto_xof_turboshake* functions are
 * standard
 extendable output functions. From input of any length, they can derive
 output of any length with the same properties as hash functions. These
 primitives are required by many post-quantum mechanisms, but can also be
 used for a wide range of applications, including key derivation, session
 encryption and more.
 * Performance of AES256-GCM and AEGIS on ARM has been improved with some
 compilers
 * Security: optblockers have been introduced in critical code paths to prevent
 compilers from introducing unwanted side channels via conditional jumps. This
 was observed on RISC-V targets with specific compilers and options.
 * Security: crypto_core_ed25519_is_valid_point() now properly rejects
 small-order points that are not in the main subgroup
 * ((nonnull)) attributes have been relaxed on some crypto_stream* functions to
 allow NULL output buffers when the output length is zero
 * A cross-compilation issue with old clang versions has been fixed
 * crypto_aead_aes256gcm_is_available is exported to JavaScript
 * Security: memory fences have been added after MAC verification in AEAD to
 prevent speculative access to plaintext before authentication is complete
 * Assembly files now include .gnu.property notes for proper IBT and Shadow
 Stack support when building with CET instrumentation.