Issue #2276183 by alexpott: Fixed Date intl support is broken, remove it.

core/config/schema/core.data_types.schema.yml

core/includes/common.inc

core/lib/Drupal/Component/Datetime/DateTimePlus.php

core/lib/Drupal/Core/Datetime/Date.php

core/lib/Drupal/Core/Datetime/DrupalDateTime.php

...modules/config_translation/src/FormElement/DateFormat.php

.../config_translation/src/Tests/ConfigTranslationUiTest.php

core/modules/datetime/datetime.module

...me/src/Plugin/Field/FieldWidget/DateTimeDefaultWidget.php

core/modules/datetime/src/Tests/DateTimeFieldTest.php

.../modules/locale/src/Tests/LocaleConfigTranslationTest.php

...grate/src/Plugin/migrate/destination/EntityDateFormat.php

...les/migrate_drupal/src/Tests/d6/MigrateDateFormatTest.php

...les/system/config/install/system.date_format.fallback.yml

...es/system/config/install/system.date_format.html_date.yml

...ystem/config/install/system.date_format.html_datetime.yml

...s/system/config/install/system.date_format.html_month.yml

...es/system/config/install/system.date_format.html_time.yml

...es/system/config/install/system.date_format.html_week.yml

...es/system/config/install/system.date_format.html_year.yml