refactor: fix `nullCoalesce.variable` errors #13136

Job	Run time
Setup PHP Version for Code Coverage	4s
Others (8.1) / Sanity Tests	2m 29s
Others (8.3) / Sanity Tests	2m 48s
Others (8.2) / Sanity Tests	3m 36s
Others (8.4) / Sanity Tests	2m 34s
SeparateProcess (8.3) / tests	3m 19s
DatabaseLive (8.2, SQLite3, 8.0) / tests	3m 48s
DatabaseLive (8.2, MySQLi, 8.0) / tests	3m 46s
DatabaseLive (8.3, Postgre, 8.0) / tests	2m 37s
SeparateProcess (8.1) / tests	3m 31s
SeparateProcess (8.4) / tests	3m 35s
DatabaseLive (8.2, SQLSRV, 8.0) / tests	3m 47s
DatabaseLive (8.2, Postgre, 8.0) / tests	49s
DatabaseLive (8.3, MySQLi, 8.0) / tests	3m 47s
DatabaseLive (8.1, MySQLi, 5.7) / tests	3m 23s
DatabaseLive (8.2, OCI8, 8.0) / tests	3m 47s
DatabaseLive (8.1, OCI8, 8.0) / tests	3m 46s
DatabaseLive (8.3, OCI8, 8.0) / tests	3m 47s
DatabaseLive (8.4, MySQLi, 8.0) / tests	3m 46s
DatabaseLive (8.4, OCI8, 8.0) / tests	3m 48s
DatabaseLive (8.3, SQLite3, 8.0) / tests	1s
DatabaseLive (8.4, SQLite3, 8.0) / tests	2m 42s
DatabaseLive (8.1, SQLSRV, 8.0) / tests	3m 46s
DatabaseLive (8.1, MySQLi, 8.0) / tests	3m 45s
DatabaseLive (8.1, SQLite3, 8.0) / tests	1s
DatabaseLive (8.3, SQLSRV, 8.0) / tests	5s
DatabaseLive (8.4, Postgre, 8.0) / tests	2m 56s
SeparateProcess (8.2) / tests	3m 36s
DatabaseLive (8.4, SQLSRV, 8.0) / tests	3m 47s
CacheLive (8.3) / Cache Live Tests	9s
DatabaseLive (8.1, Postgre, 8.0) / tests	3m 34s
CacheLive (8.2) / Cache Live Tests	45s
CacheLive (8.1) / Cache Live Tests	32s
CacheLive (8.4) / Cache Live Tests	1s
Upload coverage results to Coveralls	0s
	1h 28m 27s

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