Build fails with Xcode 26.4

[shuguenot]

Description

AppAuth 2.0.0 fails to compile with Xcode 26.4.0 (Apple clang 21) due to GNU case ranges being reclassified as a C2y extension.

Error

OIDTokenUtilities.m:64:12: error: case ranges are a C2y extension [-Werror,-Wc2y-extensions]
    case 1 ... 8:
            ^

The project enables -Werror, which promotes this new warning into a fatal error.

Environment

• Xcode 26.4.0
• AppAuth 2.0.0