chore: checkpoint before Python removal

vendor/rustls-native-certs/tests/common/mod.rs

@@ -0,0 +1,17 @@
+use std::env;
+
+/// Cargo, at least sometimes, sets SSL_CERT_FILE and SSL_CERT_DIR internally, as
+/// it uses OpenSSL. So, always unset both at the beginning of a test even if
+/// the test doesn't use either.
+///
+/// # Safety
+///
+/// This is only safe if used together with `#[serial]` because calling
+/// `[env::remove_var()]` is unsafe if another thread is running.
+///
+/// Note that `env::remove_var()` is scheduled to become unsafe in Rust
+/// Edition 2024.
+pub(crate) unsafe fn clear_env() {
+    env::remove_var("SSL_CERT_FILE");
+    env::remove_var("SSL_CERT_DIR");
+}