Script Loader: Trigger _doing_it_wrong() when wp_set_script_translations() is called before script registration

[shrivastavanolo]

This PR updates wp_set_script_translations() to trigger _doing_it_wrong() when it is called for a script that has not yet been registered.

Previously, the function silently failed because WP_Scripts::set_translations() returned false, making it difficult for developers to identify incorrect usage.

Trac ticket: https://core.trac.wordpress.org/ticket/50749

Use of AI Tools

AI assistance: Yes
Tool(s): ChatGPT
Model(s): GPT-5.1
Used for: Initial code skeleton; final implementation was edited by me.

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[github-actions]

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