Improve PHP 8.4 compatibility #11666

Job	Run time
Pre run	5s
Static Analysis: PHP	1m 16s
Lint: CSS	15s
Lint: JS	28s
E2E test: JS (1, 2)	7m 7s
Lint: PHP	38s
Unit test: JS	46s
E2E test: JS (2, 2)	3m 24s
Unit test: PHP 8.0, WP latest	1m 58s
Unit test: PHP 8.4, WP trunk	1m 45s
Unit test: PHP 8.3, WP trunk	2m 6s
Feature tests: PHP 7.4, WP latest	1m 53s
Unit test: PHP 8.2, WP trunk	2m 22s
Feature tests: PHP 8.4, WP trunk	1m 48s
Unit test: PHP 8.1, WP trunk	2m 26s
Feature tests: PHP 8.3, WP trunk	2m 3s
Unit test: PHP 8.0, WP trunk	2m 2s
Feature tests: PHP 8.2, WP trunk	1m 48s
Unit test (with coverage): PHP 8.0, WP latest	4m 4s
Feature tests: PHP 8.1, WP trunk	1m 47s
Unit test: PHP 8.0, WP latest	1m 30s
Feature tests: PHP 8.0, WP latest	1m 43s
Feature tests: PHP 7.4, WP 6.5	1m 47s
Unit test: PHP 7.4, WP latest	2m 32s
Unit test: PHP 7.4, WP latest	1m 32s
Unit test: PHP 7.4, WP 6.5	1m 58s
Unit test: PHP 7.4, WP 6.5	1m 52s
	52m 55s

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