Skip more tests on Windows

Author: bkhouri

Tests/BasicsTests/LegacyHTTPClientTests.swift

@@ -349,7 +349,9 @@ final class LegacyHTTPClientTests: XCTestCase {
         wait(for: [promise], timeout: 1)
     }
 
-    func testExponentialBackoff() {
+    func testExponentialBackoff() throws {
+        try skipOnWindowsAsTestCurrentlyFails()
+
         let count = ThreadSafeBox<Int>(0)
         let lastCall = ThreadSafeBox<Date>()
         let maxAttempts = 5