fix: enable aimdb-core/alloc by default in aimdb-knx-connector

The alloc feature was only enabled under the embassy-runtime feature flag,
but cargo publish verification builds with no features active. This caused
aimdb-core to be compiled without alloc, breaking compilation.

Mirrors the pattern already used in aimdb-mqtt-connector where
default = ["aimdb-core/alloc"] ensures aimdb-core always has alloc.

Author: lxsaah

aimdb-knx-connector/Cargo.toml

@@ -11,7 +11,7 @@ keywords = ["knx", "knxnet-ip", "building-automation", "iot", "connector"]
 categories = ["network-programming", "embedded", "asynchronous"]
 
 [features]
-default = []
+default = ["aimdb-core/alloc"]
 std = ["aimdb-core/std", "knx-pico/std", "thiserror"]
 tokio-runtime = ["std", "tokio", "uuid", "async-stream", "futures-util"]
 embassy-runtime = [