chore: Removed dotenvy

Since secrets can now be set from automation.toml the .env file was no
longer used, so dotenvy can be removed.

Cargo.toml

@@ -23,7 +23,6 @@ automation_lib = { path = "./automation_lib" }
 automation_macro = { path = "./automation_macro" }
 axum = "0.8.4"
 bytes = "1.10.1"
-dotenvy = "0.15.7"
 dyn-clone = "1.0.20"
 eui48 = { version = "1.1.0", features = [
   "disp_hexstring",
@@ -75,7 +74,6 @@ config = { version = "0.15.15", default-features = false, features = [
   "async",
   "toml",
 ] }
-dotenvy = { workspace = true }
 git-version = "0.3.9"
 google_home = { workspace = true }
 mlua = { workspace = true }