Correct issue: existing_contact select widget fails to lock fields

[bsilvern]

Overview

Locked fields are not actually locked when an existing_contact element is configured as a Select widget.

Before

Locked fields with an existing_contact Select widget were not actually locked.

After

• Locked fields with an existing_contact Select widget are locked as demonstrated by ExistingContactElementTest::testNextPrevSaveLoad() line 640.
• The test introduced in the previous PR in this series completes without error.

Technical Details

Comments

The tests are unchanged from the previous PR in this series.

[KarinG]

Jitendra approved - going to merge this now so that they will be in the next release.

[KarinG]

Bob -> note we ended up skipping this test for D10.3+

https://github.com/colemanw/webform_civicrm/blob/6.x/tests/src/FunctionalJavascript/ExistingContactElementTest.php#L532-L536

Because in D10.3 we get:

$webform->get('elements') is { }

We tried a couple of things e.g.
$elements = $webform->getElementsDecodedAndFlattened();

But could not get it to work.

Also not directly related but relevant for future:
966x: The "yaml_parser_class" setting is deprecated in drupal:10.3.0. This setting should be removed from the settings file, since its usage has been removed. See https://www.drupal.org/node/3415489. which means Drupal\Core\Serialization\Yaml is deprecated.

[bsilvern]

@KarinG OK, thanks. I'll update the test if I can find a way to support D10.3+.