Refactor string length validation in EventDefinition entity properties

Removed minimum length constraints from SemifinalistActivity and Notes properties in the EventDefinition class to simplify validation requirements. This change enhances flexibility in data entry while maintaining the maximum length restrictions.

Core/Entities/EventDefinition.cs

@@ -30,7 +30,7 @@ public class EventDefinition
 			? MinTeamSize.ToString()
 			: $"{MinTeamSize.ToString()}-{MaxTeamSize.ToString()}";
 
-    [StringLength(100, MinimumLength = 3)]
+    [StringLength(100)]
 	public string? SemifinalistActivity { get; set; }
 
 	public bool InterviewOrPresentation
@@ -53,7 +53,7 @@ public class EventDefinition
     //          || Name.Contains("Chapter")
     //          || Name.Contains("Podcast"));
 
-    [StringLength(1024, MinimumLength = 3)]
+    [StringLength(1024)]
 	public string? Notes { get; set; }
 
     [Range(0, 3)]