CI: regression since #3552069: frequent PHPUnit PostgreSQL CI job failures

Overview

Ever since #3552069: Don't require SDC components to have a schema we seem to have very frequent CI failures (see the ocean of ❌ at https://git.drupalcode.org/project/canvas/-/commits/1.x?ref_type=HEADS) in SingleDirectoryComponentTest::testDiscovery():

1) Drupal\Tests\canvas\Kernel\Plugin\Canvas\ComponentSource\SingleDirectoryComponentTest::testDiscovery
Failed asserting that two arrays are identical.
--- Expected
+++ Actual
@@ @@
     32 => 'sdc.canvas_test_sdc.two_column',
     33 => 'sdc.canvas_test_sdc.video',
     34 => 'sdc.sdc_theme_test.bar',
-    35 => 'sdc.sdc_theme_test_base.my-card-no-schema',
-    36 => 'sdc.sdc_theme_test.lib-overrides',
-    37 => 'sdc.sdc_theme_test.my-card',
+    35 => 'sdc.sdc_theme_test.lib-overrides',
+    36 => 'sdc.sdc_theme_test.my-card',
+    37 => 'sdc.sdc_theme_test_base.my-card-no-schema',
 ]

/builds/project/canvas/tests/src/Kernel/Plugin/Canvas/ComponentSource/SingleDirectoryComponentTest.php:206

Proposed resolution

User interface changes