Update symfony/intl to v7 (compatibility with drupal11 & symfony 7)

Problem/Motivation

The field_validation module currently has a Composer requirement for symfony/intl set to ^6.3.

This does not allow Symfony 7 and causes a dependency conflict when using field_validation:3.0.x-dev in a Drupal 11 project, because Drupal 11 uses Symfony 7 components.

This is the same kind of issue as #3525460, where another Composer dependency constraint was updated to allow compatibility with newer dependency versions.

In Drupal 11 projects, symfony/intl needs to allow ^7, but the current ^6.3 constraint prevents that.

Steps to reproduce

1. Start with a Drupal 11 project.
2. Require field_validation:3.0.x-dev with Composer.
3. Composer fails because the current symfony/intl:^6.3 constraint from field_validation does not allow the Symfony 7 version required by Drupal 11.

Example:

composer require drupal/field_validation:3.0.x-dev

This results in a dependency conflict involving symfony/intl, because Drupal 11 requires Symfony 7 components while the module currently requires symfony/intl:^6.3.

Proposed resolution

Update the symfony/intl requirement in composer.json for the 3.0.x branch to allow Symfony 7.

For example, change the constraint from:

"symfony/intl": "^6.3"

to:

"symfony/intl": "^6.3 || ^7.0"

Alternatively, if the project wants to align with Drupal 10.3+ and Drupal 11 supported Symfony versions, the constraint could be adjusted as appropriate.

This should allow the module to be installed in Drupal 11 projects while preserving compatibility with Drupal 10.

Remaining tasks

• Update the symfony/intl constraint in composer.json.
• Verify that the module can be installed with Drupal 11.
• Run tests to confirm there are no issues with Symfony 7.

User interface changes

None.

API changes

None.