Update tests and source files to avoid depset union.

Progress towards https://github.com/bazelbuild/bazel/issues/5817

RELNOTES: None.
PiperOrigin-RevId: 245265538

tools/build_rules/java_rules_skylark.bzl

diff --git a/tools/build_rules/java_rules_skylark.bzl b/tools/build_rules/java_rules_skylark.bzl
index f837fe4..5bc76a5 100644
--- a/tools/build_rules/java_rules_skylark.bzl
+++ b/tools/build_rules/java_rules_skylark.bzl
@@ -36,8 +36,8 @@
 
     jars = ctx.files.jars
     neverlink_jars = ctx.files.neverlink_jars
-    compile_time_jars += jars + neverlink_jars
-    runtime_jars += jars
+    compile_time_jars = depset(jars + neverlink_jars, transitive = [compile_time_jars])
+    runtime_jars = depset(jars, transitive = [runtime_jars])
     compile_time_jars_list = compile_time_jars.to_list()  # TODO: This is weird.
 
     build_output = class_jar.path + ".build_output"