Remove virtualThreadsEnabled from OltpProperties

Author: Mike Turbe

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/export/otlp/OtlpProperties.java

@@ -79,11 +79,6 @@ public class OtlpProperties extends StepRegistryProperties {
 	 */
 	private TimeUnit baseTimeUnit = TimeUnit.MILLISECONDS;
 
-	/**
-	 * Whether virtual threads should be used for publishing metrics.
-	 */
-	private boolean virtualThreadsEnabled = false;
-
 	public String getUrl() {
 		return this.url;
 	}