fix: clean up unnecessay mut and dead code warnings

crates/core/src/kernel/snapshot/log_segment.rs

@@ -515,8 +515,6 @@ pub(super) async fn list_log_files(
 
 #[cfg(test)]
 pub(super) mod tests {
-    use std::str::FromStr;
-
     use deltalake_test::utils::*;
 
     use super::*;

crates/core/src/operations/convert_to_delta.rs

@@ -226,7 +226,7 @@ impl ConvertToDeltaBuilder {
     }
 
     /// Consume self into CreateBuilder with corresponding add actions, schemas and operation meta
-    async fn into_create_builder(mut self) -> Result<CreateBuilder, Error> {
+    async fn into_create_builder(self) -> Result<CreateBuilder, Error> {
         // Use the specified log store. If a log store is not provided, create a new store from the specified path.
         // Return an error if neither log store nor path is provided
         let log_store = if let Some(log_store) = self.log_store {

crates/core/src/operations/merge/mod.rs

@@ -1320,7 +1320,7 @@ async fn execute(
         build_case(copy_when, copy_then)?,
     ));
 
-    let mut new_columns = {
+    let new_columns = {
         let plan = projection.into_unoptimized_plan();
         let mut fields: Vec<Expr> = plan
             .schema()

crates/gcp/tests/context.rs

@@ -98,12 +98,6 @@ impl StorageIntegration for GcpIntegration {
     }
 }
 
-impl GcpIntegration {
-    fn delete_bucket(&self) -> std::io::Result<ExitStatus> {
-        gs_cli::delete_bucket(self.bucket_name.clone())
-    }
-}
-
 /// small wrapper around google api
 pub mod gs_cli {
     use super::set_env_if_not_set;