chore: changing vaadin-core dependency to have provided scope.

[czp13]

Description

Based on Marc's problem:

Failed to collect dependencies at com.vaadin.flow.ai:form-filler-addon:jar:0.1.0: Failed to read artifact descriptor for com.vaadin.flow.ai:form-filler-addon:jar:0.1.0: Could not find artifact com.vaadin:vaadin-bom:pom:24.1-SNAPSHOT

and Artur's recommended way to handle Vaadin versions.

This will solve the problem, when a developer is adding the form-filler-addon dependency to a maven project and having a specific vaadin-core version, now with this, the version should come from the project the addon dependency is used.

Fixes # (issue):

• https://github.com/vaadin/form-filler-addon/issues/122

Type of change

• [x] Bugfix
• [ ] Feature

Checklist

• [x] I have read the contribution guide: https://vaadin.com/docs/latest/guide/contributing/overview/
• [x] I have added a description following the guideline.
• [x] The issue is created in the corresponding repository and I have referenced it.
• [x] I have added tests to ensure my change is effective and works as intended.
• [x] New and existing tests are passing locally with my change.
• [x] I have performed self-review and corrected misspellings.

Additional for Feature type of change

• [ ] Enhancement / new feature was discussed in a corresponding GitHub issue and Acceptance Criteria were created.