If `HardwareBreakpointTestBase.supports_hw_breakpoints()` returns False,
`SimpleHWBreakpointTest.does_not_support_hw_breakpoints()` returns None,
so the test runs and fails. However, it should be skipped instead.
The test was added in #146602, while `supports_hw_breakpoints()` was
changed in #146609, which was landed earlier despite having a bigger
number.
ccdb71932a