Remove outdated comment

build.gradle

@@ -128,7 +128,6 @@ subprojects {
     "org.elasticsearch.client:transport:${version}": ':client:transport',
     "org.elasticsearch.test:framework:${version}": ':test:framework',
     "org.elasticsearch.distribution.integ-test-zip:elasticsearch:${version}": ':distribution:integ-test-zip',
-    // TODO: don't use a hardcoded version here, introspect it from Version.java
     "org.elasticsearch.distribution.zip:elasticsearch:${bwcVersion}": ':distribution:bwc-zip',
     "org.elasticsearch.distribution.zip:elasticsearch:${version}": ':distribution:zip',
     "org.elasticsearch.distribution.tar:elasticsearch:${version}": ':distribution:tar',