Fix linter errors: derive Default for AuthZBackend and OpenFGAAuth (lakekeeper#1476)

Author: romusz

crates/authz-openfga/src/config.rs

@@ -82,9 +82,10 @@ pub struct OpenFGAConfig {
     pub max_batch_check_size: usize,
 }
 
-#[derive(Clone, Serialize, Deserialize, PartialEq, veil::Redact)]
+#[derive(Clone, Default, Serialize, Deserialize, PartialEq, veil::Redact)]
 #[serde(rename_all = "snake_case")]
 pub enum OpenFGAAuth {
+    #[default]
     Anonymous,
     ClientCredentials {
         client_id: String,
@@ -97,12 +98,6 @@ pub enum OpenFGAAuth {
     ApiKey(String),
 }
 
-impl Default for OpenFGAAuth {
-    fn default() -> Self {
-        Self::Anonymous
-    }
-}
-
 fn deserialize_openfga_config<'de, D>(deserializer: D) -> Result<Option<OpenFGAConfig>, D::Error>
 where
     D: Deserializer<'de>,

crates/lakekeeper/src/config.rs

@@ -369,8 +369,9 @@ where
         .serialize(serializer)
 }
 
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Default, Clone, PartialEq)]
 pub enum AuthZBackend {
+    #[default]
     AllowAll,
     External(String),
 }
@@ -403,12 +404,6 @@ impl Serialize for AuthZBackend {
     }
 }
 
-impl Default for AuthZBackend {
-    fn default() -> Self {
-        Self::AllowAll
-    }
-}
-
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
 pub enum SecretBackend {
     #[serde(alias = "kv2", alias = "Kv2")]