Use mock server in test #403

Job	Run time
Tests (ubuntu-latest, 7.4, lowest, ^5)	1m 32s
Tests (ubuntu-latest, 7.4, highest, ^5)	1m 34s
Tests (ubuntu-latest, 8.0, lowest, ^5)	1m 31s
Tests (ubuntu-latest, 8.0, highest, ^5)	1m 47s
Tests (ubuntu-latest, 8.0, highest, ^6)	1m 40s
Tests (ubuntu-latest, 8.1, lowest, ^6)	1m 35s
Tests (ubuntu-latest, 8.0, lowest, ^6)	1m 30s
Tests (ubuntu-latest, 8.1, highest, ^5)	1m 31s
Tests (ubuntu-latest, 8.2, lowest, ^5)	1m 40s
Tests (ubuntu-latest, 8.1, lowest, ^5)	1m 36s
Tests (ubuntu-latest, 8.1, highest, ^6)	1m 52s
Tests (ubuntu-latest, 8.2, lowest, ^7)	1m 45s
Tests (ubuntu-latest, 8.2, lowest, ^6)	1m 38s
Tests (ubuntu-latest, 8.3, lowest, ^5)	1m 34s
Tests (ubuntu-latest, 8.2, highest, ^6)	1m 36s
Tests (ubuntu-latest, 8.2, highest, ^5)	1m 33s
Tests (ubuntu-latest, 8.2, highest, ^7)	1m 36s
Tests (ubuntu-latest, 8.3, lowest, ^6)	1m 31s
Tests (ubuntu-latest, 8.3, highest, ^5)	1m 41s
Tests (macos-latest, 8.0, highest, ^5)	2m 48s
Tests (ubuntu-latest, 8.3, highest, ^7)	1m 43s
Tests (ubuntu-latest, 8.3, highest, ^6)	1m 40s
Tests (windows-latest, 8.0, highest, 5.4.2)	6h 0m 4s
Tests (ubuntu-latest, 8.3, lowest, ^7)	1m 37s
	6h 38m 34s

Provide feedback