fixup: remove env var; run in single test

Author: not-matthias

crates/cargo-codspeed/tests/cargo_config.rs

@@ -2,9 +2,13 @@ use std::process::Command;
 
 mod helpers;
 use helpers::*;
-
 #[test]
 fn test_cargo_config_rustflags() {
+    test_cargo_config_without_rustflags_env();
+    test_cargo_config_with_rustflags_env();
+}
+
+fn test_cargo_config_without_rustflags_env() {
     let tmp_dir = setup("tests/cargo_config.in", Project::Simple);
 
     // Test that cargo bench works with the custom flag
@@ -34,7 +38,6 @@ fn test_cargo_config_rustflags() {
     teardown(tmp_dir);
 }
 
-#[test]
 fn test_cargo_config_with_rustflags_env() {
     let tmp_dir = setup("tests/cargo_config.in", Project::Simple);
 
@@ -66,4 +69,6 @@ fn test_cargo_config_with_rustflags_env() {
     );
 
     teardown(tmp_dir);
+
+    std::env::remove_var("RUSTFLAGS");
 }