fix(java-auto-test): ensure thread safety when finding and parsing PsiJavaFile

Previously, the `PsiJavaFile` was loaded without ensuring thread safety, which could lead to race conditions and inconsistent results. This commit introduces a `runReadAction` block to guarantee that the file is loaded and parsed in a thread-safe manner, preventing potential issues with concurrent access.

Author: phodal

java/src/main/kotlin/cc/unitmesh/idea/service/JavaAutoTestService.kt

@@ -161,8 +161,10 @@ class JavaAutoTestService : AutoTestService() {
         ): GradleRunConfiguration? {
             val name = virtualFile.name
 
-            val psiFile: PsiJavaFile = PsiManager.getInstance(project).findFile(virtualFile) as? PsiJavaFile ?: return null
-            val canonicalName = runReadAction { psiFile.packageName + "." + virtualFile.nameWithoutExtension }
+            val canonicalName = runReadAction {
+                val psiFile: PsiJavaFile = PsiManager.getInstance(project).findFile(virtualFile) as? PsiJavaFile ?: return@runReadAction null
+                psiFile.packageName + "." + virtualFile.nameWithoutExtension
+            } ?: return null
 
             val runManager = RunManager.getInstance(project)