refactor: remove deprecated `system/bootstrap.php` #14327

Job	Run time
Setup PHP Version for Code Coverage	4s
Others (8.3) / Sanity Tests	2m 31s
Others (8.5) / Sanity Tests	2m 40s
Others (8.2) / Sanity Tests	3m 45s
Others (8.4) / Sanity Tests	2m 29s
CacheLive (8.2) / Cache Live Tests	2m 25s
CacheLive (8.5) / Cache Live Tests	2m 6s
SeparateProcess (8.2) / tests	3m 46s
SeparateProcess (8.3) / tests	3m 35s
CacheLive (8.3) / Cache Live Tests	2m 12s
CacheLive (8.4) / Cache Live Tests	2m 2s
DatabaseLive (8.5, MySQLi, 8.0) / tests	5m 37s
DatabaseLive (8.3, MySQLi, 8.0) / tests	5m 35s
DatabaseLive (8.4, Postgre, 8.0) / tests	2m 37s
DatabaseLive (8.4, MySQLi, 8.0) / tests	4m 41s
SeparateProcess (8.4) / tests	3m 27s
SeparateProcess (8.5) / tests	3m 28s
DatabaseLive (8.2, SQLSRV, 8.0) / tests	5m 52s
DatabaseLive (8.3, SQLSRV, 8.0) / tests	5m 25s
DatabaseLive (8.5, Postgre, 8.0) / tests	2m 57s
DatabaseLive (8.3, Postgre, 8.0) / tests	2m 41s
DatabaseLive (8.4, SQLite3, 8.0) / tests	2m 29s
DatabaseLive (8.3, SQLite3, 8.0) / tests	2m 11s
DatabaseLive (8.2, OCI8, 8.0) / tests	8m 8s
DatabaseLive (8.3, OCI8, 8.0) / tests	6m 15s
DatabaseLive (8.4, SQLSRV, 8.0) / tests	5m 5s
DatabaseLive (8.5, OCI8, 8.0) / tests	7m 33s
DatabaseLive (8.2, MySQLi, 5.7) / tests	3m 50s
DatabaseLive (8.5, SQLSRV, 8.0) / tests	5m 7s
DatabaseLive (8.4, OCI8, 8.0) / tests	6m 50s
DatabaseLive (8.2, SQLite3, 8.0) / tests	2m 53s
DatabaseLive (8.2, MySQLi, 8.0) / tests	5m 24s
DatabaseLive (8.2, Postgre, 8.0) / tests	3m 21s
DatabaseLive (8.5, SQLite3, 8.0) / tests	2m 12s
Upload coverage results to Coveralls / coveralls	49s
	2h 12m 2s

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