fix CI for PyPI upload

Author: haifeng-jin

pip_build.py

@@ -15,6 +15,10 @@
 ]
 
 
+def ignore_files(_, filenames):
+    return [f for f in filenames if f.endswith("_test.py")]
+
+
 def build():
     if os.path.exists(build_directory):
         raise ValueError(f"Directory already exists: {build_directory}")
@@ -24,7 +28,9 @@ def build():
         # Copy sources (`keras_tuner/` directory and setup files) to build
         # directory
         os.mkdir(build_directory)
-        shutil.copytree(package, os.path.join(build_directory, package))
+        shutil.copytree(
+            package, os.path.join(build_directory, package), ignore=ignore_files
+        )
         for fname in to_copy:
             shutil.copy(fname, os.path.join(f"{build_directory}", fname))
         os.chdir(build_directory)