refactor: fix phpstan errors in `Events` #13301

Job	Run time
Setup PHP Version for Code Coverage	4s
Others (8.2) / Sanity Tests	3m 39s
Others (8.3) / Sanity Tests	2m 30s
Others (8.4) / Sanity Tests	2m 33s
Others (8.1) / Sanity Tests	2m 28s
SeparateProcess (8.3) / tests	3m 35s
SeparateProcess (8.4) / tests	3m 19s
SeparateProcess (8.1) / tests	3m 23s
SeparateProcess (8.2) / tests	3m 14s
DatabaseLive (8.1, MySQLi, 8.0) / tests	5m 13s
DatabaseLive (8.3, Postgre, 8.0) / tests	2m 38s
DatabaseLive (8.3, MySQLi, 8.0) / tests	5m 45s
DatabaseLive (8.2, SQLite3, 8.0) / tests	3m 9s
DatabaseLive (8.4, Postgre, 8.0) / tests	2m 38s
DatabaseLive (8.2, Postgre, 8.0) / tests	3m 0s
DatabaseLive (8.4, OCI8, 8.0) / tests	6m 0s
DatabaseLive (8.4, SQLite3, 8.0) / tests	2m 36s
DatabaseLive (8.1, Postgre, 8.0) / tests	2m 32s
DatabaseLive (8.2, OCI8, 8.0) / tests	6m 49s
DatabaseLive (8.1, SQLite3, 8.0) / tests	2m 44s
DatabaseLive (8.3, SQLSRV, 8.0) / tests	4m 31s
DatabaseLive (8.2, MySQLi, 8.0) / tests	4m 53s
DatabaseLive (8.1, SQLSRV, 8.0) / tests	5m 32s
DatabaseLive (8.3, SQLite3, 8.0) / tests	2m 33s
DatabaseLive (8.2, SQLSRV, 8.0) / tests	6m 8s
DatabaseLive (8.4, SQLSRV, 8.0) / tests	4m 23s
DatabaseLive (8.1, OCI8, 8.0) / tests	5m 56s
DatabaseLive (8.3, OCI8, 8.0) / tests	6m 10s
DatabaseLive (8.4, MySQLi, 8.0) / tests	4m 12s
DatabaseLive (8.1, MySQLi, 5.7) / tests	3m 1s
CacheLive (8.2) / Cache Live Tests	2m 9s
CacheLive (8.1) / Cache Live Tests	2m 3s
CacheLive (8.4) / Cache Live Tests	1m 56s
CacheLive (8.3) / Cache Live Tests	2m 7s
Upload coverage results to Coveralls / coveralls	46s
	2h 4m 9s

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