Revert "Use mimalloc in line with datafusion-cli"

On Fly.io's free tier (with the 256MB limit), it causes OOM errors when doing
`CREATE EXTERNAL TABLE` + `CREATE TABLE AS`, so disabling it for now.

This reverts commit 4b89565.

Cargo.toml

@@ -32,7 +32,6 @@ hashbrown = { version = "0.12", features = ["raw"] }
 hex = ">=0.4.0"
 itertools = ">=0.10.0"
 log = "0.4"
-mimalloc = { version = "*", default-features = false }
 moka = { version = "0.9.3", default_features = false, features = ["future", "atomic64", "quanta"] }
 object_store = "0.3.0"
 pretty_env_logger = "0.4"

src/main.rs

@@ -10,7 +10,6 @@ use std::{
 use clap::Parser;
 
 use futures::{future::join_all, Future, FutureExt};
-use mimalloc::MiMalloc;
 
 use pretty_env_logger::env_logger;
 use seafowl::{
@@ -30,9 +29,6 @@ use tokio::sync::broadcast::{channel, Sender};
 #[cfg(feature = "frontend-postgres")]
 use seafowl::frontend::postgres::run_pg_server;
 
-#[global_allocator]
-static GLOBAL: MiMalloc = MiMalloc;
-
 extern crate pretty_env_logger;
 #[macro_use]
 extern crate log;