Add support for parameters that were added later

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Example:

resolve_block_template was added in 5.8, but the third $fallback_template parameter was only added in 5.9.

This also often happens with hooks, see #17.

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Sometimes function signatures are changed later, for example in 6.3 the bool $in_footer param of wp_enqueue_script() became array $args | bool $in_footer. So now one should pass an array, but a bool is still supported for back compat.