GH-1192 - Migrate code base to jSpecify for nullness verification.

spring-modulith-actuator/pom.xml

@@ -16,6 +16,11 @@
 
 	<dependencies>
 
+    <dependency>
+      <groupId>org.jspecify</groupId>
+      <artifactId>jspecify</artifactId>
+    </dependency>
+
 		<dependency>
 			<groupId>org.springframework.modulith</groupId>
 			<artifactId>spring-modulith-runtime</artifactId>

spring-modulith-actuator/src/main/java/org/springframework/modulith/actuator/autoconfigure/package-info.java

@@ -1,5 +1,5 @@
 /**
  * Autoconfiguration for Spring Modulith actuators.
  */
-@org.springframework.lang.NonNullApi
+@org.jspecify.annotations.NullMarked
 package org.springframework.modulith.actuator.autoconfigure;

spring-modulith-actuator/src/main/java/org/springframework/modulith/actuator/package-info.java

@@ -1,5 +1,5 @@
 /**
  * Spring Boot actuator support for Spring Modulith.
  */
-@org.springframework.lang.NonNullApi
+@org.jspecify.annotations.NullMarked
 package org.springframework.modulith.actuator;