Options: Invalidate object cache when update_option() DB write fails

[himanshupathak95]

Trac ticket: https://core.trac.wordpress.org/ticket/26402

When update_option() fails to update the database (e.g., option deleted directly from DB while still in cache), the stale cached value may persist indefinitely with persistent object caching.

This PR -

• Added cache invalidation in update_option() when $wpdb->update() returns false.
• Clears alloptions entry (if autoloaded) or individual option cache to ensure no stale data is served.
• Adds tests to verify that the alloptions cache no longer contains the option.

[github-actions]

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[github-actions]

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