Devtools' integration test dependencies may contain duplicates with different versions

[wilkinsona]

As seen by @snicoll:

-rw-r--r--  1 snicoll  staff   678K Aug 11 15:04 spring-beans-5.3.0-M2.jar
-rw-r--r--  1 snicoll  staff   678K Aug  6 17:38 spring-beans-5.3.0-SNAPSHOT.jar
-rw-r--r--  1 snicoll  staff   1.2M Aug 11 15:04 spring-boot-2.4.0-SNAPSHOT.jar
-rw-r--r--  1 snicoll  staff   1.4M Aug 11 15:04 spring-boot-autoconfigure-2.4.0-SNAPSHOT.jar
-rw-r--r--  1 snicoll  staff   217K Aug 11 15:04 spring-boot-devtools-2.4.0-SNAPSHOT.jar
-rw-r--r--  1 snicoll  staff   4.7K Aug 11 15:04 spring-boot-starter-2.4.0-SNAPSHOT.jar
-rw-r--r--  1 snicoll  staff   4.6K Aug 11 15:04 spring-boot-starter-json-2.4.0-SNAPSHOT.jar
-rw-r--r--  1 snicoll  staff   4.6K Aug 11 15:04 spring-boot-starter-logging-2.4.0-SNAPSHOT.jar
-rw-r--r--  1 snicoll  staff   4.7K Aug 11 15:04 spring-boot-starter-tomcat-2.4.0-SNAPSHOT.jar
-rw-r--r--  1 snicoll  staff   4.7K Aug 11 15:04 spring-boot-starter-web-2.4.0-SNAPSHOT.jar
-rw-r--r--  1 snicoll  staff   1.2M Jul 28 16:03 spring-context-5.3.0-M1.jar
-rw-r--r--  1 snicoll  staff   1.2M Aug 11 15:04 spring-context-5.3.0-M2.jar
-rw-r--r--  1 snicoll  staff   1.2M Aug  6 17:38 spring-context-5.3.0-SNAPSHOT.jar
-rw-r--r--  1 snicoll  staff   1.4M Jul 28 16:03 spring-core-5.3.0-M1.jar
-rw-r--r--  1 snicoll  staff   1.4M Aug 11 15:04 spring-core-5.3.0-M2.jar
-rw-r--r--  1 snicoll  staff   1.4M Aug  6 17:38 spring-core-5.3.0-SNAPSHOT.jar
-rw-r--r--  1 snicoll  staff   276K Jul 28 16:03 spring-expression-5.3.0-M1.jar
-rw-r--r--  1 snicoll  staff   276K Aug 11 15:04 spring-expression-5.3.0-M2.jar
-rw-r--r--  1 snicoll  staff   276K Aug  6 17:38 spring-expression-5.3.0-SNAPSHOT.jar

We're using a Copy task. Switching to Sync should make sure that the output doesn't contain anything that isn't in the latest input.