Contact Form: avoid conflicts when using the old version of the Contact Form feature

[jeherve]

This is a follow-up to #33050.

Right now, the contact form feature is loaded from the Contact Form package by default:

jetpack/projects/plugins/jetpack/modules/contact-form.php

Lines 23 to 36 in 0173104

	/**
	* Whether to load the newer Jetpack Forms package.
	*
	* @use add_filter( 'jetpack_contact_form_use_package', '__return_true' );
	* @module contact-form
	*
	* @since 11.8
	*
	* @param bool $load_contact_form_package Load Jetpack Forms package. Default to false.
	*/
	if ( apply_filters( 'jetpack_contact_form_use_package', true ) ) {
	Jetpack_Forms::load_contact_form();
	return true; // Not returning true will cause the module to become deactivated.
	}

Some site owners may decide to continue to load the contact form feature from the old codebase instead:

add_filter( 'jetpack_contact_form_use_package', '__return_false' );

When you do so, you run into issues with how the blocks are registered, as discussed in p1696362451002639-slack-CDD9LQRSN

Related Epic: #32401

---

Related Epic: the old form code will eventually be removed in #30551

[chrisbliss18]

Could we ask the reporter of this issue why they are using the old version? Maybe we can help them fix their specific issue so that it is no longer a conflict.

It would be nice to trigger a _doing_it_wrong() warning to indicate that this is deprecated functionality and will be removed in a future version.

[jeherve]

Could we ask the reporter of this issue why they are using the old version? Maybe we can help them fix their specific issue so that it is no longer a conflict.

Discussion is happening here:
p1697469538876579/1696362451.002639-slack-CDD9LQRSN

It seems it may not be an issue anymore. 👍

It would be nice to trigger a _doing_it_wrong() warning to indicate that this is deprecated functionality and will be removed in a future version.

The work behind the deprecation is currently tracked in #30551.

[jeherve]

It seems it may not be an issue anymore. 👍

Given where we stand, I'll close this issue as "won't fix", and we can focus on proper deprecation instead.