SC-45754 Migrate to dateless license headers

[claire-villard-sonarsource]

No description provided.

[sonar-review-alpha]

Summary

This PR removes date information from copyright headers across all Java and JavaScript files in the project, changing from Copyright (C) 2009-2025 SonarSource Sàrl to Copyright (C) SonarSource Sàrl.

The change affects 47 files total:

• 24 Java source files and their variations
• 23 JavaScript and CSS files (configuration, build scripts, and web components)

This is a straightforward maintenance task that eliminates the need to update year ranges in copyright notices annually.

What reviewers should know

What to check:

• Verify all copyright headers follow the new dateless format consistently
• Confirm no unintended changes beyond the copyright line (all diffs show only the date range removal)
• No functional code changes, build changes, or dependency modifications

Pattern to review:
All changes follow this single pattern:

- * Copyright (C) 2009-2025 SonarSource Sàrl
+ * Copyright (C) SonarSource Sàrl

No blockers: This is a purely administrative update with zero risk to functionality or testing.

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🗣️ Give feedback

[sonar-review-alpha]

LGTM! ✅

Clean, mechanical change — every file has exactly one line modified (the copyright year range removed), no functional code touched, and the change is applied consistently across all 47 files.

🗣️ Give feedback

[jerome-chetelat-sonarsource]

LGTM