[test] Move cctest/test-object to unittests

... /objects/object-unittest.

Bug: v8:12781
Change-Id: I48156098cf2ce216b8231a05dd68cfa96e04911d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3607388Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: 王澳 <wangao.james@bytedance.com>
Cr-Commit-Position: refs/heads/main@{#80215}

test/cctest/BUILD.gn

@@ -234,7 +234,6 @@ v8_source_set("cctest_sources") {
     "test-lockers.cc",
     "test-managed.cc",
     "test-mementos.cc",
-    "test-object.cc",
     "test-orderedhashtable.cc",
     "test-parsing.cc",
     "test-persistent-handles.cc",