refactor: Unify all json.(loads|dumps) usage to utils.json (#28702)

Co-authored-by: Eyal Ezer <eyal.ezer@ge.com>

tests/integration_tests/migrations/7e67aecbf3f1_chart_ds_constraint__tests.py

@@ -15,9 +15,10 @@
 # specific language governing permissions and limitations
 # under the License.
 
-import json
 from importlib import import_module
 
+from superset.utils import json
+
 chart_ds_constraint = import_module(
     "superset.migrations.versions." "2023-03-27_12-30_7e67aecbf3f1_chart_ds_constraint",
 )

tests/integration_tests/migrations/ad07e4fdbaba_rm_time_range_endpoints_from_qc_3__test.py

@@ -14,9 +14,10 @@
 # KIND, either express or implied.  See the License for the
 # specific language governing permissions and limitations
 # under the License.
-import json
 from importlib import import_module
 
+from superset.utils import json
+
 rm_time_range_endpoints_from_qc_3 = import_module(
     "superset.migrations.versions."
     "2022-04-18_11-20_ad07e4fdbaba_rm_time_range_endpoints_from_qc_3",

tests/integration_tests/migrations/c747c78868b6_migrating_legacy_treemap__tests.py

@@ -14,10 +14,10 @@
 # KIND, either express or implied.  See the License for the
 # specific language governing permissions and limitations
 # under the License.
-import json
 
 from superset.app import SupersetApp
 from superset.migrations.shared.migrate_viz import MigrateTreeMap
+from superset.utils import json
 
 treemap_form_data = """{
   "adhoc_filters": [

tests/integration_tests/migrations/fb13d49b72f9_better_filters__tests.py

@@ -14,9 +14,10 @@
 # KIND, either express or implied.  See the License for the
 # specific language governing permissions and limitations
 # under the License.
-import json
 from importlib import import_module
 
+from superset.utils import json
+
 better_filters = import_module(
     "superset.migrations.versions." "2018-12-11_22-03_fb13d49b72f9_better_filters",
 )