tests: port assertEquals() with delta to assertEqualsWithDelta()

assertEquals() in phpunit 9.5 no longer takes a delta parameter
and has assertEqualsWithDelta() as a replacement. This means
float get compared without a delta atm, and a recent phpunit
release (9.5.25) has made float comparisons stricter resulting in
test suite errors such as:

1) SubtaskTimeTrackingModelTest::testCalculateSubtaskTime
Total spent
Failed asserting that 3.3000000000000003 matches expected 3.3.
tests/units/Model/SubtaskTimeTrackingModelTest.php:186

This replaces all assertEquals() calls that pass a delta value
with assertEqualsWithDelta().

tests/units/Model/ProjectActivityTest.php

@@ -28,7 +28,7 @@ class ProjectActivityTest extends Base
         $events = $projectActivity->getQuery()->desc('id')->findAll();
 
         $this->assertCount(2, $events);
-        $this->assertEquals(time(), $events[0]['date_creation'], '', 1);
+        $this->assertEqualsWithDelta(time(), $events[0]['date_creation'], 1, '');
         $this->assertEquals(TaskModel::EVENT_UPDATE, $events[0]['event_name']);
         $this->assertEquals(TaskModel::EVENT_CLOSE, $events[1]['event_name']);
     }