python3Packages.buildPythonPackage: ban pytestFlagsArray

- the `xorg` package set has been deprecated, packages have moved to the top level.

- `python3Packages.buildPythonPackage` and `python3Packages.buildPythonApplication` now throw errors in the presence of `pytestFlagsArray`.

  Please use [`pytestFlags` and `(enabled|disabled)(TestPaths|Tests|TestMarks)`](#using-pytestcheckhook) instead.

  If modifying the Nix expression is not feasible, users can remediate the error by overriding `pytestFlagsArray` with `null` or `[ ]`.

- `python3Packages.pygame` has been been renamed to `python3Packages.pygame-original`, the attribute `python3Packages.pygame` will from python 3.14 default to the more actively maintained `python3Packages.pygame-ce`

- `fastly` has been updated to major version 14. For more information, you can check the [release notes](https://github.com/fastly/cli/releases/tag/v14.0.0)

    "dependencies"

    "optional-dependencies"

    "build-system"

    # Deprecated arguments

    "pytestFlagsArray"

  ];

  extendDrvArgs =

      # Longer-term we should get rid of `checkPhase` and use `installCheckPhase`.

      installCheckPhase = attrs.checkPhase;

    }

    // (

      let

        deprecatedFlagNotEmpty =

          attrs ? pytestFlagsArray && attrs.pytestFlagsArray != null && attrs.pytestFlagsArray != [ ];

        pos = builtins.unsafeGetAttrPos "pytestFlagsArray" attrs;

      in

      {

        ${if deprecatedFlagNotEmpty then "pytestFlagsArray" else null} = throw ''

          buildPythonPackage: Deprecated flag pytestFlagsArray found at ${pos.file}:${toString pos.line}

            Use pytestFlags or (enabled|disabled)(TestPaths|Tests|TestMarks) instead.

        '';

      }

    )

    //

      lib.mapAttrs

        (