fix typo + remove branch from CI

.github/workflows/build.yml

@@ -6,7 +6,6 @@ on:
     - master
     # For testing.
     - actions
-    - serena/battery-stuff
     tags:
       - "v*.*"
     paths-ignore:

Common/Battery/AppleBatteryClient.m

@@ -29,7 +29,7 @@ void _powerSourceRunLoopCallback(void * __unused ctx) {
 // You may ask,
 // "Why an entire class?
 // Why not just call the UIDevice/IOKitPowerSource functions every time getCurrentBatteryCapacity() is called?"
-// Well, calling the UIDevice/IOKitPowerSource very frequently is expensive
+// Well, calling the UIDevice/IOKitPowerSource functions very frequently (every second, it seems?) is expensive
 // So, instead, I made a class with a cached batteryLevel property
 // that only gets set when it needs to.
 @implementation AppleBatteryClient