boards: remove firmware feature gates

boards/kakute-f7-mini-v3/Cargo.toml

@@ -10,7 +10,6 @@ version.workspace = true
 workspace = true
 
 [features]
-firmware = []
 lidar-lite-v3 = []
 
 [dependencies]
@@ -20,6 +19,5 @@ platform-stm32f7 = { path = "../../platforms/stm32f7" }
 [[bin]]
 name = "kaptan-kakute-f7-mini-v3"
 path = "src/main.rs"
-required-features = ["firmware"]
 test = false
 bench = false