refactor: fix `nullCoalesce.variable` errors #13130

Job	Run time
Setup PHP Version for Code Coverage	2s
Others (8.1) / Sanity Tests	2m 55s
Others (8.4) / Sanity Tests	2m 38s
Others (8.2) / Sanity Tests	4m 30s
Others (8.3) / Sanity Tests	2m 35s
SeparateProcess (8.1) / tests	3m 26s
SeparateProcess (8.3) / tests	3m 9s
SeparateProcess (8.2) / tests	3m 22s
DatabaseLive (8.1, SQLite3, 8.0) / tests	2m 37s
SeparateProcess (8.4) / tests	3m 33s
DatabaseLive (8.1, SQLSRV, 8.0) / tests	5m 10s
DatabaseLive (8.3, Postgre, 8.0) / tests	2m 29s
DatabaseLive (8.4, SQLSRV, 8.0) / tests	5m 19s
DatabaseLive (8.1, Postgre, 8.0) / tests	2m 29s
DatabaseLive (8.2, SQLite3, 8.0) / tests	3m 23s
DatabaseLive (8.1, OCI8, 8.0) / tests	6m 12s
DatabaseLive (8.4, SQLite3, 8.0) / tests	2m 49s
DatabaseLive (8.3, OCI8, 8.0) / tests	6m 22s
DatabaseLive (8.2, MySQLi, 8.0) / tests	5m 33s
DatabaseLive (8.4, OCI8, 8.0) / tests	5m 56s
DatabaseLive (8.3, SQLSRV, 8.0) / tests	5m 17s
DatabaseLive (8.1, MySQLi, 5.7) / tests	3m 22s
DatabaseLive (8.2, OCI8, 8.0) / tests	6m 30s
DatabaseLive (8.3, SQLite3, 8.0) / tests	2m 58s
DatabaseLive (8.4, MySQLi, 8.0) / tests	4m 6s
DatabaseLive (8.3, MySQLi, 8.0) / tests	4m 46s
DatabaseLive (8.2, Postgre, 8.0) / tests	3m 9s
CacheLive (8.2) / Cache Live Tests	2m 3s
DatabaseLive (8.4, Postgre, 8.0) / tests	2m 33s
DatabaseLive (8.1, MySQLi, 8.0) / tests	5m 25s
DatabaseLive (8.2, SQLSRV, 8.0) / tests	6m 3s
CacheLive (8.3) / Cache Live Tests	2m 8s
CacheLive (8.1) / Cache Live Tests	2m 11s
CacheLive (8.4) / Cache Live Tests	1m 57s
Upload coverage results to Coveralls	0s
	2h 6m 57s

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