Remove default formula for active power and energy (#55)

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.

Author: cwasicki

RELEASE_NOTES.md

@@ -8,6 +8,7 @@ explicitly configured.
 ## Upgrading
 
 * Update assets client to v0.3.0.
+* Default formulas for AC active power and energy are removed.
 
 ## New Features
 

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.