Tests

Fix "offset might not exist" false-positives when offset is a expression #22881

Job	Run time
Determine levels tests matrix	20s
Integration tests (windows-latest)	22s
Integration tests (ubuntu-latest)	23s
Tests (8.2, windows-latest)	24s
Tests (8.2, ubuntu-latest)	33s
Tests (8.3, ubuntu-latest)	21s
Tests (8.3, windows-latest)	25s
Tests (8.5, windows-latest)	26s
Tests (8.4, ubuntu-latest)	33s
Tests with old PHPUnit (8.1, windows-latest)	25s
Tests with old PHPUnit (8.0, ubuntu-latest)	24s
Tests with old PHPUnit (7.4, ubuntu-latest)	21s
Tests with old PHPUnit (8.1, ubuntu-latest)	22s
Tests with old PHPUnit (7.4, windows-latest)	25s
Tests (8.4, windows-latest)	23s
Tests (8.5, ubuntu-latest)	22s
Tests with old PHPUnit (8.0, windows-latest)	22s
Levels tests	1s
	6m 52s

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