Remove management.tracing.enabled from documentation

Closes gh-38626

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/tracing/TracingProperties.java

@@ -31,11 +31,6 @@ import org.springframework.boot.context.properties.ConfigurationProperties;
 @ConfigurationProperties("management.tracing")
 public class TracingProperties {
 
-	/**
-	 * Whether auto-configuration of tracing is enabled.
-	 */
-	private boolean enabled = true;
-
 	/**
 	 * Sampling configuration.
 	 */
@@ -56,14 +51,6 @@ public class TracingProperties {
 	 */
 	private final Brave brave = new Brave();
 
-	public boolean isEnabled() {
-		return this.enabled;
-	}
-
-	public void setEnabled(boolean enabled) {
-		this.enabled = enabled;
-	}
-
 	public Sampling getSampling() {
 		return this.sampling;
 	}