GH-10083: Apply Nullability to spring-integration-mail

Related to: #10083

Signed-off-by: Jiandong Ma <[email protected]>

Author: mjd507

spring-integration-mail/src/main/java/org/springframework/integration/mail/config/package-info.java

@@ -1,7 +1,5 @@
 /**
  * Provides classes for configuration - parsers, namespace handlers.
  */
-@NullMarked
+@org.jspecify.annotations.NullMarked
 package org.springframework.integration.mail.config;
-
-import org.jspecify.annotations.NullMarked;

spring-integration-mail/src/main/java/org/springframework/integration/mail/dsl/package-info.java

@@ -1,7 +1,5 @@
 /**
  * Provides Mail Components for the Java DSL.
  */
-@NullMarked
+@org.jspecify.annotations.NullMarked
 package org.springframework.integration.mail.dsl;
-
-import org.jspecify.annotations.NullMarked;

spring-integration-mail/src/main/java/org/springframework/integration/mail/event/package-info.java

@@ -1,7 +1,5 @@
 /**
  * Events generated by the mail module
  */
-@NullMarked
+@org.jspecify.annotations.NullMarked
 package org.springframework.integration.mail.event;
-
-import org.jspecify.annotations.NullMarked;

spring-integration-mail/src/main/java/org/springframework/integration/mail/package-info.java

@@ -1,7 +1,5 @@
 /**
  * Base package for Mail support.
  */
-@NullMarked
+@org.jspecify.annotations.NullMarked
 package org.springframework.integration.mail;
-
-import org.jspecify.annotations.NullMarked;

spring-integration-mail/src/main/java/org/springframework/integration/mail/support/package-info.java

@@ -1,7 +1,5 @@
 /**
  * Provides classes to support email.
  */
-@NullMarked
+@org.jspecify.annotations.NullMarked
 package org.springframework.integration.mail.support;
-
-import org.jspecify.annotations.NullMarked;

spring-integration-mail/src/main/java/org/springframework/integration/mail/transformer/package-info.java

@@ -1,7 +1,5 @@
 /**
  * Provides classes related to transforming mail messages.
  */
-@NullMarked
+@org.jspecify.annotations.NullMarked
 package org.springframework.integration.mail.transformer;
-
-import org.jspecify.annotations.NullMarked;