Tests: remove @testable import PackageCollectionsModel

Use the newly extended APIs for testing and use a non-testable import of
the package, avoiding a recompilation.

Author: compnerd

Tests/PackageCollectionsModelTests/PackageCollectionModelTests.swift

@@ -14,7 +14,7 @@ import Foundation
 import _InternalTestSupport
 import XCTest
 
-@testable import PackageCollectionsModel
+import PackageCollectionsModel
 
 class PackageCollectionModelTests: XCTestCase {
     typealias Model = PackageCollectionModel.V1

Tests/PackageCollectionsTests/PackageCollectionValidationTests.swift

@@ -14,7 +14,7 @@ import Foundation
 import XCTest
 
 import PackageCollections
-@testable import PackageCollectionsModel
+import PackageCollectionsModel
 import PackageModel
 
 class PackageCollectionValidationTests: XCTestCase {