fix libkrb5 and decimal shard build

[henderkes]

What does this PR do?

fixes zig-cc 0.16 being stricter. Silly of krb5 to define -Werror on it when they assign a const pointer to a non-const pointer type.

Checklist before merging

If your PR involves the changes mentioned below and completed the action, please tick the corresponding option.
If a modification is not involved, please skip it directly.

• If you modified *.php or *.json, run them locally to ensure your changes are valid:
  • composer cs-fix
  • composer analyse
  • composer test
  • bin/spc dev:sort-config
• If it's an extension or dependency update, please ensure the following:
  • Add your test combination to src/globals/test-extensions.php.
  • If adding new or fixing bugs, add commit message containing extension test or test extensions to trigger full test suite.

[crazywhalecc]

``

[henderkes]

https://github.com/static-php/packages/actions/runs/24497908683/job/71597138154

waiting for this to pass before merging

[henderkes]

Well those are fixed, but ext-intl segfaults on zig 0.16 with aarch64.