Increase sampling rate for a flaky test

The test fails when it is run in the CI, increasing
the sampling won't solve the problem, just it will
fail less ofter. There are already two different open
issues to address and fix these flaky tests. See the
links below:

#249
#70

Signed-off-by: Daniel Zullo <[email protected]>

Author: daniel-zullo-frequenz

tests/timeseries/_formula_engine/test_formula_composition.py

@@ -23,7 +23,7 @@ async def test_formula_composition(  # pylint: disable=too-many-locals
         mocker: MockerFixture,
     ) -> None:
         """Test the composition of formulas."""
-        mockgrid = MockMicrogrid(grid_side_meter=False, sample_rate_s=0.05)
+        mockgrid = MockMicrogrid(grid_side_meter=False, sample_rate_s=0.1)
         mockgrid.add_batteries(3)
         mockgrid.add_solar_inverters(2)
         await mockgrid.start(mocker)