c/migrations/tests: configure for cloud in data migration table test

otherwise migrations don't pass validation

src/v/cluster/tests/data_migration_table_test.cc

@@ -11,6 +11,7 @@
 #include "cluster/data_migration_table.h"
 #include "cluster/data_migration_types.h"
 #include "commands.h"
+#include "config/configuration.h"
 #include "container/fragmented_vector.h"
 #include "data_migrated_resources.h"
 #include "data_migration_types.h"
@@ -83,6 +84,12 @@ create_groups(std::vector<std::string_view> strings) {
 
 struct data_migration_table_fixture : public seastar_test {
     ss::future<> SetUpAsync() override {
+        config::shard_local_cfg().cloud_storage_enabled.set_value(true);
+        config::shard_local_cfg()
+          .cloud_storage_disable_archiver_manager.set_value(true);
+        config::shard_local_cfg().cloud_storage_enable_remote_write.set_value(
+          true);
+
         co_await resources.start();
         co_await topics.start(ss::sharded_parameter(
           [this] { return std::ref(resources.local()); }));
@@ -110,6 +117,7 @@ struct data_migration_table_fixture : public seastar_test {
             auto p_cnt = random_generators::get_int(1, 64);
 
             topic_configuration cfg(tp_ns.ns, tp_ns.tp, p_cnt, 3);
+            cfg.properties.shadow_indexing = model::shadow_indexing_mode::full;
             ss::chunked_fifo<partition_assignment> assignments;
             for (auto i = 0; i < p_cnt; ++i) {
                 assignments.push_back(