Class UpdateUserInput

Represents user input for updating an existing user. This class is used to validate the data before updating the user in the database.

• email: The user's email address (optional, must be valid if provided).
• firstname: The user's first name (optional, must be between 2 and 100 characters if provided).
• lastname: The user's last name (optional, must be between 2 and 100 characters if provided).
• role: the user's role, must be one of the valid roles defined in the Roles enum (optional).

The class uses the following decorators:

• @Field(): Exposes the property in the GraphQL schema (via type-graphql).
• @IsEmail(): Ensures the email is valid (only if the email is provided).
• @Length(): Ensures the string length is within the specified bounds (for firstname, lastname).
• @IsOptional(): Indicates that the field is optional.
• @IsIn(): ensures the role is a valid role as defined in the Roles enum (optional).