ci: remove flaky stdin test

Author: Guanran928

rdict-core/src/rdict.rs

@@ -409,9 +409,7 @@ pub fn output_english_plain(result: &ToEnglish) -> Result<String> {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use assert_cmd::Command;
     use mockito::{Matcher, Server};
-    use predicates::prelude::*;
 
     #[test]
     fn test_contains_cjk_with_cjk() {
@@ -433,17 +431,6 @@ mod tests {
         assert!(!contains_cjk(""));
     }
 
-    #[test]
-    fn test_cmd_stdin_empty() -> Result<(), Box<dyn std::error::Error>> {
-        let mut cmd = Command::cargo_bin("rdict")?;
-        cmd.write_stdin("")
-            .assert()
-            .failure()
-            .stderr(predicate::str::contains("No word specified"));
-
-        Ok(())
-    }
-
     #[tokio::test]
     async fn test_fetch_word_html_success_with_mock_server() {
         let mut server = Server::new_async().await;