Clear MeterRegistry before each test case

Closes gh-38604

Author: mhalbritter

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/test/MetricsIntegrationTests.java

@@ -30,6 +30,7 @@
 import io.micrometer.core.instrument.simple.SimpleConfig;
 import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
 import jakarta.servlet.DispatcherType;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.annotation.Autowired;
@@ -99,6 +100,11 @@ class MetricsIntegrationTests {
 	@Autowired
 	private MeterRegistry registry;
 
+	@BeforeEach
+	void setUp() {
+		this.registry.clear();
+	}
+
 	@SuppressWarnings("unchecked")
 	@Test
 	void restTemplateIsInstrumented() {