Update to spice2x-25-04-25 (pre-apply)

> broken commit

external/cpu_features/cmake/README.md

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+# CMake build instructions
+
+## Recommended usage : Incorporating cpu_features into a CMake project
+
+For API / ABI compatibility reasons, it is recommended to build and use
+cpu_features in a subdirectory of your project or as an embedded dependency.
+
+This is similar to the recommended usage of the googletest framework
+( https://github.com/google/googletest/blob/main/googletest/README.md )
+
+Build and use step-by-step
+
+
+1- Download cpu_features and copy it in a sub-directory in your project.
+or add cpu_features as a git-submodule in your project
+
+2- You can then use the cmake command `add_subdirectory()` to include
+cpu_features directly and use the `cpu_features` target in your project.
+
+3- Add the `CpuFeatures::cpu_features` target to the `target_link_libraries()` section of
+your executable or of your library.
+
+## Disabling tests
+
+CMake default options for cpu_features is `Release` built type with tests
+enabled. To disable testing set cmake `BUILD_TESTING` variable to `OFF`.
+e.g.
+```sh
+cmake -S. -Bbuild -DBUILD_TESTING=OFF
+```