fix(compress): keep test-only parameter import local

The new context-parameter projection test is compiled only in test builds,
but its constant was imported at module scope. Keep the import in the test
module so normal clippy builds remain warning-free under `-D warnings`.

Test Plan:
- `git diff --cached --check` -- passed.
- Root capped clippy rerun after this commit.

rust/src/zstd_compress_params_api.rs

@@ -21,8 +21,7 @@ use crate::zstd_compress_params::{
     ZSTD_rust_params_resolveEnableLdm, ZSTD_rust_params_resolveExternalRepcodeSearch,
     ZSTD_rust_params_resolveExternalSequenceValidation, ZSTD_rust_params_resolveMaxBlockSize,
     ZSTD_rust_params_resolveRowMatchFinderMode, ZSTD_CONTENTSIZE_UNKNOWN,
-    ZSTD_RUST_CPM_CREATE_CDICT, ZSTD_RUST_CPM_NO_ATTACH_DICT, ZSTD_RUST_PS_AUTO,
-    ZSTD_RUST_PS_DISABLE, ZSTD_RUST_PS_ENABLE,
+    ZSTD_RUST_CPM_CREATE_CDICT, ZSTD_RUST_PS_AUTO, ZSTD_RUST_PS_DISABLE, ZSTD_RUST_PS_ENABLE,
 };
 use std::mem::size_of;
 use std::os::raw::{c_int, c_void};
@@ -1192,6 +1191,7 @@ pub unsafe extern "C" fn ZSTD_CCtxParams_registerSequenceProducer(
 mod tests {
     use super::*;
     use crate::errors::{ERR_getErrorCode, ERR_isError};
+    use crate::zstd_compress_params::ZSTD_RUST_CPM_NO_ATTACH_DICT;
     use std::mem::{align_of, offset_of, size_of, MaybeUninit};
     use std::sync::atomic::{AtomicUsize, Ordering};