Tests: repair test for Windows

The index was incorrectly `2` for non-Darwin targets. Windows does not have the autolink extract phase which results in a off-by-one index. Use the test helper to exclude the auto-link-extract job to support Linux and Windows similarly.

Author: compnerd

Tests/SwiftDriverTests/SwiftDriverTests.swift

@@ -5026,10 +5026,12 @@ final class SwiftDriverTests: XCTestCase {
  _ = try driverWithEmptySDK.planBuild()
 
  var driver = try Driver(args: ["swiftc", "foo.swift", "-sdk", "/"])
- let plannedJobs = try driver.planBuild()
+ let plannedJobs = try driver.planBuild().removingAutolinkExtractJobs()
+
  XCTAssertTrue(plannedJobs[0].commandLine.contains(subsequence: ["-sdk", .path(.absolute(try .init(validating: "/")))]))
+
  if !driver.targetTriple.isDarwin {
- XCTAssertFalse(plannedJobs[2].commandLine.contains(subsequence: ["-L", .path(.absolute(try .init(validating: "/usr/lib/swift")))]))
+ XCTAssertFalse(plannedJobs[1].commandLine.contains(subsequence: ["-L", .path(.absolute(try .init(validating: "/usr/lib/swift")))]))
  }
  }