FoundationEssentialTests: elide some tests on Windows

Windows does not have the concept of a "root" user, instead all users
have rights assigned to them with a capabilities system. As there is no
equivalent for `euid`, simply elide this suite on Windows for now.

Author: compnerd

Tests/FoundationEssentialsTests/FileManager/FileManagerTests.swift

@@ -523,7 +523,8 @@ final class FileManagerTests : XCTestCase {
             XCTAssertFalse($0.fileExists(atPath: "does_not_exist"))
         }
     }
-    
+
+#if !os(Windows)
     func testFileAccessAtPath() throws {
         guard getuid() != 0 else {
             // Root users can always access anything, so this test will not function when run as root
@@ -552,7 +553,8 @@ final class FileManagerTests : XCTestCase {
             }
         }
     }
-    
+#endif
+
     func testFileSystemAttributesAtPath() throws {
         try FileManagerPlayground {
             "Foo"