diff --git a/core/drupalci.yml b/core/drupalci.yml
index cd92d8102d..412350e10f 100644
--- a/core/drupalci.yml
+++ b/core/drupalci.yml
@@ -3,49 +3,15 @@
 # https://www.drupal.org/drupalorg/docs/drupal-ci/customizing-drupalci-testing
 _phpunit_testgroups_to_execute: &testgroups
   # Default: all of Drupal core's test suite runs.
-  testgroups: '--all'
+  testgroups: '--class "\Drupal\Tests\block\Kernel\Migrate\d7\MigrateBlockContentTranslationTest"'
   # Alternative: run only the tests for one particular module.
   # testgroups: '--module ckeditor5'
 build:
   assessment:
     testing:
-      # Run code quality checks.
-      container_command.commit-checks:
-        commands:
-          - "core/scripts/dev/commit-code-check.sh --drupalci"
-        halt-on-fail: true
-      # run_tests task is executed several times in order of performance speeds.
-      # halt-on-fail can be set on the run_tests tasks in order to fail fast.
-      # suppress-deprecations is false in order to be alerted to usages of
-      # deprecated code.
-      run_tests.phpunit:
-        types: 'PHPUnit-Unit'
-        suppress-deprecations: false
-        halt-on-fail: false
-        <<: *testgroups
       run_tests.kernel:
         types: 'PHPUnit-Kernel'
         suppress-deprecations: false
         halt-on-fail: false
         <<: *testgroups
-      run_tests.build:
-        # Limit concurrency due to disk space concerns.
-        concurrency: 15
-        types: 'PHPUnit-Build'
-        suppress-deprecations: false
-        halt-on-fail: false
-        <<: *testgroups
-      run_tests.functional:
-        types: 'PHPUnit-Functional'
-        suppress-deprecations: false
-        halt-on-fail: false
-        <<: *testgroups
-      run_tests.javascript:
-        concurrency: 15
-        types: 'PHPUnit-FunctionalJavascript'
-        suppress-deprecations: false
-        halt-on-fail: false
-        <<: *testgroups
-      # Run nightwatch testing.
-      # @see https://www.drupal.org/project/drupal/issues/2869825
-      nightwatchjs: {}
+        repeat: 5000
diff --git a/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php b/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php
index 7790e3500d..2f233ff8bb 100644
--- a/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php
+++ b/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php
@@ -86,29 +86,6 @@ public function checkConfigSchema(TypedConfigManagerInterface $typed_config, $co
       $errors[] = $this->checkValue($key, $value);
     }
     $errors = array_merge(...$errors);
-    // Also perform explicit validation. Note this does NOT require every node
-    // in the config schema tree to have validation constraints defined.
-    $violations = $this->schema->validate();
-    $filtered_violations = array_filter(
-      iterator_to_array($violations),
-      fn (ConstraintViolation $v) => !static::isViolationForIgnoredPropertyPath($v),
-    );
-    $validation_errors = array_map(
-      fn (ConstraintViolation $v) => sprintf("[%s] %s", $v->getPropertyPath(), (string) $v->getMessage()),
-      $filtered_violations
-    );
-    // If config validation errors are encountered for a contrib module, avoid
-    // failing the test (which would be too disruptive for the ecosystem), but
-    // trigger a deprecation notice instead.
-    if (!empty($validation_errors) && $this->isContribViolation()) {
-      @trigger_error(sprintf("The '%s' configuration contains validation errors. Invalid config is deprecated in drupal:10.2.0 and will be required to be valid in drupal:11.0.0. The following validation errors were found:\n\t\t- %s",
-        $config_name,
-        implode("\n\t\t- ", $validation_errors)
-      ), E_USER_DEPRECATED);
-    }
-    else {
-      $errors = array_merge($errors, $validation_errors);
-    }
     if (empty($errors)) {
       return TRUE;
     }
diff --git a/core/lib/Drupal/Core/Extension/InfoParserDynamic.php b/core/lib/Drupal/Core/Extension/InfoParserDynamic.php
index 8298223a37..4f4b0e0b88 100644
--- a/core/lib/Drupal/Core/Extension/InfoParserDynamic.php
+++ b/core/lib/Drupal/Core/Extension/InfoParserDynamic.php
@@ -51,7 +51,7 @@ public function parse($filename) {
         throw new InfoParserException('Missing required keys (' . implode(', ', $missing_keys) . ') in ' . $filename);
       }
       if (!isset($parsed_info['core_version_requirement'])) {
-        if (str_starts_with($filename, 'core/') || str_starts_with($filename, $this->root . '/core/')) {
+        if (str_starts_with($filename, 'core/') || str_starts_with($filename, $this->root . DIRECTORY_SEPARATOR . 'core/')) {
           // Core extensions do not need to specify core compatibility: they are
           // by definition compatible so a sensible default is used. Core
           // modules are allowed to provide these for testing purposes.