…(vudaltsov)This PR was squashed before being merged into the 3.4 branch (closes#30736).Discussion----------[Validator] Fix annotation default for@count and@Length| Q             | A| ------------- | ---| Branch?       | 3.4| Bug fix?      | yes| New feature?  | no| BC breaks?    | no| Deprecations? | no| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->| Fixed tickets | n/a| License       | MIT| Doc PR        | is it worth mentioning?`Count` and `Length` constraints allow to pass the exact value as the constructor argument when used in code.```phpnew Length(5);// is same asnew Length(['min' => 5, 'max' => 5]);```At the same time when using them as annotations, `@Assert\Length(5)` throws `The options "" do not exist in constraint Symfony\\Component\\Validator\\Constraints\\Length` (fix for ugly exception is proposed in#30737). This happens because annotation's default value is passed as `value`. Since `Length` does not have a default option, `value` is replaced with `''`.This PR fixes this inconsistency.Commits-------7bfb8c1 [Validator] Fix annotation default for@count and@Length

…tsov)This PR was squashed before being merged into the 3.4 branch (closes#30737).Discussion----------[Validator] Improve constraint default option check| Q             | A| ------------- | ---| Branch?       | 3.4| Bug fix?      | yes| New feature?  | no| BC breaks?    | no| Deprecations? | no| Tests pass?   | yes| Fixed tickets | n/a| License       | MIT| Doc PR        | n/aAny constraint without default option used as annotation with unnamed first argument (for example, `@Assert\Collection(1)`) throws an exception with an ugly message `The options "" do not exist in constraint Collection`.This PR makes constraint check the default option in the annotation case in the same way it checks it in the "real" code case. So the exception will be `No default option is configured for constraint Collection.`Commits-------915912e [Validator] Improve constraint default option check