test: Use correct extensions for fixture tests (#6539)

crates/swc_css_lints/tests/lints.rs

@@ -52,7 +52,7 @@ fn pass(input: PathBuf) {
 
 #[testing::fixture("tests/rules/fail/**/input.css")]
 fn fail(input: PathBuf) {
-    let stderr_path = input.parent().unwrap().join("output.stderr");
+    let stderr_path = input.parent().unwrap().join("output.swc-stderr");
     let config_path = input.parent().unwrap().join("config.json");
     let lint_config =
         serde_json::from_str::<LintConfig>(&fs::read_to_string(config_path).unwrap()).unwrap();

crates/swc_css_parser/tests/fixture.rs

@@ -547,7 +547,7 @@ fn stylesheet_span_visualizer(input: PathBuf, config: Option<ParserConfig>) {
     .unwrap_err();
 
     output
-        .compare_to_file(&dir.join("span.rust-debug"))
+        .compare_to_file(&dir.join("span.swc-stderr"))
         .unwrap();
 }