Build: Switch integ-test-zip to OSS-only (elastic#31866)

We mistakenly enabled bundling of the default distribution's bin scripts
into the `integ-test-zip` artifact used by plugin authors to test plugins.
These didn't change the version of Elasticsearch used for testing but as
a side effect changed the LICENSE.txt from the Apache 2 license to the
Elastic license. We really didn't mean for that to happen. The bin script
and the elasticsearch-sql-cli jar file bundled into the distribution are
indeed governed by the Elastic license but we didn't intend for them to be
in the testing artifact in the first place. This removes them and fixes
the license of the `integ-test-zip` artifact.

Author: nik9000

distribution/archives/build.gradle

@@ -102,7 +102,7 @@ Closure commonZipConfig = {
 
 task buildIntegTestZip(type: Zip) {
   configure(commonZipConfig)
-  with archiveFiles(transportModulesFiles, 'zip', false)
+  with archiveFiles(transportModulesFiles, 'zip', true)
 }
 
 task buildZip(type: Zip) {
@@ -193,7 +193,7 @@ subprojects {
     onlyIf toolExists
     doLast {
       final String licenseFilename
-      if (project.name.contains('oss-')) {
+      if (project.name.contains('oss-') || project.name == 'integ-test-zip') {
         licenseFilename = "APACHE-LICENSE-2.0.txt"
       } else {
         licenseFilename = "ELASTIC-LICENSE.txt"