MDL-71389 various: changes to unittests due to php8 changes:

- some engine error messages changed
- some warning levels changed
- the carriage return symbol randomly appears
- one phpunit assertion fails and not really representative of anything

lib/phpunit/tests/basic_test.php

@@ -96,7 +96,6 @@ class core_phpunit_basic_testcase extends basic_testcase {
         $this->assertEquals(1, '1');
         $this->assertEquals(null, '');
 
-        $this->assertNotEquals(1, '1 ');
         $this->assertNotEquals(0, '');
         $this->assertNotEquals(null, '0');
         $this->assertNotEquals(array(), '');