Remove default formula for active power and energy

With support for formulas derived from the component graph via assets
API, this should not be used anymore to not silently default to a
wrong formula.

Signed-off-by: cwasicki <126617870+cwasicki@users.noreply.github.com>

Author: cwasicki

src/frequenz/gridpool/_microgrid_config.py

@@ -51,19 +51,6 @@ def __post_init__(self) -> None:
                 "please use 'AC_POWER_ACTIVE' instead."
             )
 
-        defaults = {
-            "AC_POWER_ACTIVE",
-            "AC_ENERGY_ACTIVE",
-            "AC_ENERGY_ACTIVE_CONSUMED",
-            "AC_ENERGY_ACTIVE_DELIVERED",
-        }
-
-        for metric in defaults:
-            if metric not in self.formula:
-                self.formula[metric] = "+".join(
-                    [f"#{cid}" for cid in self._default_cids()]
-                )
-
     def cids(self, metric: str = "") -> list[int]:
         """Get component IDs for this component.