Fix 1.73.0 clippy warnings (#2674)

cli/src/lib.rs

@@ -942,7 +942,7 @@ fn new(
                 std::env::set_current_dir(parent)?;
 
                 let cluster = cfg.provider.cluster.clone();
-                let programs = cfg.programs.entry(cluster).or_insert(BTreeMap::new());
+                let programs = cfg.programs.entry(cluster).or_default();
                 if programs.contains_key(&name) {
                     return Err(anyhow!("Program already exists"));
                 }

lang/syn/src/idl/parse/file.rs

@@ -137,7 +137,7 @@ pub fn parse(
         .map(|a| a.ident.to_string())
         .collect::<HashSet<_>>();
 
-    let error_name = error.map(|e| e.name).unwrap_or_else(|| "".to_string());
+    let error_name = error.map(|e| e.name).unwrap_or_default();
 
     // All types that aren't in the accounts section, are in the types section.
     for ty_def in ty_defs {