Ensure consistent $expire casting to (int) in wp_cache_set_multiple() and wp_cache_add_multiple() functions

[dilipbheda]

While reviewing the wp_cache_* functions (e.g., wp_cache_add(), wp_cache_add_multiple(), wp_cache_replace(), wp_cache_set(), wp_cache_set_multiple()), I noticed inconsistencies regarding how the $expire parameter is handled:

• In some functions, $expire is explicitly cast to an integer (int) $expire before passing to $wp_object_cache methods.
• In others, $expire is passed directly without casting.

The attached patch ensures consistent integer casting for the $expire argument across all cache-related wrapper functions, improving type safety and alignment with how object caches typically expect expiration times.

References:

• wp_cache_add()
• wp_cache_add_multiple()
• wp_cache_replace()
• wp_cache_set()
• wp_cache_set_multiple()

[SergeyBiryukov]

In 60206:

Cache API: Consistently pass the $expire value as an integer in cache functions.

Follow-up to [52700].

Props dilipbheda.
Fixes #63364.