Remove @testable import from swift tests (pytorch#11101)

Author: shoumikhin

extension/apple/ExecuTorch/__tests__/ModuleTest.swift

@@ -6,8 +6,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-@testable import ExecuTorch
-
+import ExecuTorch
 import XCTest
 
 class ModuleTest: XCTestCase {

extension/apple/ExecuTorch/__tests__/TensorTest.swift

@@ -6,8 +6,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-@testable import ExecuTorch
-
+import ExecuTorch
 import XCTest
 
 class TensorTest: XCTestCase {

extension/apple/ExecuTorch/__tests__/ValueTest.swift

@@ -6,8 +6,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-@testable import ExecuTorch
-
+import ExecuTorch
 import XCTest
 
 class ValueTest: XCTestCase {