Remove assemble from build task when assemble removed

Removes the `assemble` task from the `build` task when we have
removed `assemble` from the project. We removed `assemble` from
projects that aren't published so our releases will be faster. But
That broke CI because CI builds with `gradle precommit build` and,
it turns out, that `build` includes `check` and `assemble`. With
this change CI will only run `check` for projects without an
`assemble`.

Original commit: elastic/x-pack-elasticsearch@d01b0df1d9

plugin/bwc/build.gradle

@@ -31,7 +31,9 @@ subprojects {
   }
   if (enabled) {
     apply plugin: 'distribution'
+    // Not published so no need to assemble
     tasks.remove(assemble)
+    build.dependsOn.remove('assemble')
 
     def (String major, String minor, String bugfix) = bwcVersion.split('\\.')
     def (String currentMajor, String currentMinor, String currentBugfix) = version.split('\\.')

qa/build.gradle

@@ -6,6 +6,7 @@ gradle.projectsEvaluated {
     Task assemble = project.tasks.findByName('assemble')
     if (assemble) {
       project.tasks.remove(assemble)
+      project.build.dependsOn.remove('assemble')
     }
   }
 }