Issue #3425150 by godotislate, longwave: Symfony deprecations in Constraint plugins

...ation/Constraint/RequiredConfigDependenciesConstraint.php

...Plugin/Validation/Constraint/EntityHasFieldConstraint.php

...n/Validation/Constraint/ImmutablePropertiesConstraint.php

...lugin/Validation/Constraint/ExtensionExistsConstraint.php

...on/Plugin/Validation/Constraint/ComplexDataConstraint.php

...lidation/Plugin/Validation/Constraint/CountConstraint.php

...lidation/Plugin/Validation/Constraint/EmailConstraint.php

...in/Validation/Constraint/EntityBundleExistsConstraint.php

...idation/Plugin/Validation/Constraint/LengthConstraint.php

...lidation/Plugin/Validation/Constraint/RegexConstraint.php

...on/Plugin/Validation/Constraint/UniqueFieldConstraint.php

...alidation/Plugin/Validation/Constraint/UuidConstraint.php

...tion/Plugin/Validation/Constraint/ValidKeysConstraint.php

...Validation/Constraint/ToolbarItemDependencyConstraint.php

...gin/Validation/Constraint/UniqueLabelInListConstraint.php

.../src/Plugin/Validation/Constraint/TestFieldConstraint.php

.../Plugin/Validation/Constraint/FileExtensionConstraint.php

...s/file/src/Plugin/Validation/Constraint/FileUriUnique.php