Tests: fully remove @testable import Basics

These do not require additonal APIs to be exposed, simply convert to
regular import of the Basics module.

Author: compnerd

Tests/BuildTests/BuildPlanTests.swift

@@ -10,7 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-@testable import Basics
+import Basics
 @testable import Build
 
 @testable

Tests/CommandsTests/SwiftCommandStateTests.swift

@@ -10,7 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-@testable import Basics
+import Basics
 @testable import Build
 @testable import Commands
 @testable import CoreCommands

Tests/PackageLoadingTests/ManifestLoaderCacheTests.swift

@@ -10,7 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-@testable import Basics
+import Basics
 @testable import PackageLoading
 import PackageModel
 import _InternalTestSupport

Tests/PackageModelTests/SwiftSDKTests.swift

@@ -10,7 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-@testable import Basics
+import Basics
 
 @_spi(SwiftPMInternal)
 @testable import PackageModel

Tests/PackageModelTests/ToolsetTests.swift

@@ -10,7 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-@testable import Basics
+import Basics
 @testable import PackageModel
 import _InternalTestSupport
 import XCTest

Tests/SourceControlTests/RepositoryManagerTests.swift

@@ -10,7 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-@testable import Basics
+import Basics
 import _Concurrency
 import PackageModel
 import _InternalTestSupport

Tests/WorkspaceTests/AuthorizationProviderTests.swift

@@ -11,7 +11,7 @@
 //===----------------------------------------------------------------------===//
 import Foundation
 
-@testable import Basics
+import Basics
 import _InternalTestSupport
 import Workspace
 import Testing