Update Sodium Compat to 1.21.2 for better PHP 8.5 support

[paragoninitiativeenterprises]

Version 1.21.2 is mostly to prevent deprecation warnings on PHP 8.5. These should never be encountered in practice (as the only file in scope was a SplFixedArray polyfill for PHP 5.2, which should never be executed on PHP 8.5), but for completeness the poylfill was updated.

• ​https://github.com/paragonie/sodium_compat/releases/tag/v1.21.1
• ​https://github.com/paragonie/sodium_compat/releases/tag/v1.21.2
• ​https://github.com/paragonie/sodium_compat/compare/v1.21.1...v1.21.2

Previously, #61686

[TobiasBg]

See #63962 for the ticket handling this deprecation in WP Core.

[SergeyBiryukov]

In 60787:

Upgrade/Install: Update sodium_compat to v1.21.2.

Version 1.21.2 is mostly to prevent deprecation warnings on PHP 8.5. These should never be encountered in practice (as the only file in scope was an SplFixedArray polyfill for PHP 5.2, which should never be executed on PHP 8.5), but for completeness the polyfill was updated.

References:

• ​sodium_compat 1.21.2 release notes
• ​Full list of changes in sodium_compat 1.21.2

Follow-up to [55699], [58752], [58753].

Props paragoninitiativeenterprises, jrf, johnbillion, TobiasBg, SergeyBiryukov.
Fixes #64008.

[SergeyBiryukov]

In 60795:

Coding Standards: Add specific sniff exclusions for serialize functions in sodium_compat.

These are necessary for a passing PHP Compatibility scan.

Follow-up to [47735], [60787].

See #64008.