test: use mock environment variables in maa-dirs tests

Change environment variables is not thread-safe, use a mock struct to avoid conflict.
Because rust support ZST, so in normal case, there should be no overhead.

crates/maa-cli/src/installer/maa_cli.rs

@@ -1,6 +1,7 @@
 use std::{collections::BTreeMap, time::Duration};
 
 use anyhow::{anyhow, Context, Result};
+use maa_dirs::MAA_CLI_EXE;
 use semver::Version;
 use serde::Deserialize;
 use tokio::runtime::Runtime;
@@ -15,9 +16,6 @@ use crate::{
     dirs::{self, Ensure},
 };
 
-const MAA_CLI_NAME: &str = "maa";
-const MAA_CLI_EXE: &str = constcat::concat!(MAA_CLI_NAME, std::env::consts::EXE_SUFFIX);
-
 pub fn update(args: &CommonArgs) -> Result<()> {
     let config = CLI_CONFIG.cli_config().with_args(args);
 

crates/maa-dirs/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "maa-dirs"
-version = "0.1.1"
+version = "0.1.2"
 edition = "2021"
 license.workspace = true
 homepage.workspace = true
@@ -11,3 +11,6 @@ constcat = { workspace = true }
 directories = { workspace = true }
 dunce = { workspace = true }
 log = { workspace = true }
+
+[dev-dependencies]
+tempfile.workspace = true