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/TransitionTest.php

@@ -34,7 +34,7 @@ class TransitionTest extends Base
         $this->assertEquals('', $transitions[0]['name']);
         $this->assertEquals('admin', $transitions[0]['username']);
         $this->assertEquals(1, $transitions[0]['user_id']);
-        $this->assertEquals(time(), $transitions[0]['date'], '', 3);
+        $this->assertEqualsWithDelta(time(), $transitions[0]['date'], 3, '');
         $this->assertEquals(3600, $transitions[0]['time_spent']);
     }