refactor: fix `nullCoalesce.variable` errors #13124

Job	Run time
Setup PHP Version for Code Coverage	2s
Others (8.3) / Sanity Tests	2m 44s
Others (8.1) / Sanity Tests	2m 44s
Others (8.2) / Sanity Tests	4m 49s
Others (8.4) / Sanity Tests	2m 45s
SeparateProcess (8.2) / tests	3m 31s
SeparateProcess (8.3) / tests	3m 54s
SeparateProcess (8.4) / tests	3m 54s
DatabaseLive (8.1, MySQLi, 8.0) / tests	4m 51s
SeparateProcess (8.1) / tests	3m 16s
DatabaseLive (8.2, OCI8, 8.0) / tests	8m 1s
DatabaseLive (8.2, Postgre, 8.0) / tests	3m 32s
DatabaseLive (8.3, OCI8, 8.0) / tests	7m 17s
DatabaseLive (8.3, MySQLi, 8.0) / tests	4m 33s
DatabaseLive (8.3, SQLite3, 8.0) / tests	2m 58s
DatabaseLive (8.1, Postgre, 8.0) / tests	2m 54s
DatabaseLive (8.3, Postgre, 8.0) / tests	2m 35s
DatabaseLive (8.2, MySQLi, 8.0) / tests	6m 14s
DatabaseLive (8.4, OCI8, 8.0) / tests	6m 11s
DatabaseLive (8.4, MySQLi, 8.0) / tests	4m 56s
DatabaseLive (8.2, SQLite3, 8.0) / tests	3m 53s
DatabaseLive (8.4, Postgre, 8.0) / tests	3m 4s
DatabaseLive (8.3, SQLSRV, 8.0) / tests	4m 45s
DatabaseLive (8.1, SQLite3, 8.0) / tests	2m 50s
DatabaseLive (8.2, SQLSRV, 8.0) / tests	5m 40s
DatabaseLive (8.4, SQLSRV, 8.0) / tests	6m 33s
DatabaseLive (8.1, OCI8, 8.0) / tests	6m 20s
CacheLive (8.1) / Cache Live Tests	2m 12s
CacheLive (8.4) / Cache Live Tests	2m 1s
DatabaseLive (8.1, MySQLi, 5.7) / tests	3m 18s
DatabaseLive (8.4, SQLite3, 8.0) / tests	2m 32s
DatabaseLive (8.1, SQLSRV, 8.0) / tests	5m 37s
CacheLive (8.2) / Cache Live Tests	2m 15s
CacheLive (8.3) / Cache Live Tests	1m 58s
Upload coverage results to Coveralls / coveralls	50s
	2h 15m 29s

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