[Bug]: Outdated CMake Version in CONTRIBUTING.md

### Describe the issue

[Link](https://github.com/google/googletest/blob/main/CONTRIBUTING.md#requirements-for-contributors)
There is following information:
>[Python](https://www.python.org/) v3.6 or newer (for running some of the tests and re-generating certain source files from templates)
[CMake](https://cmake.org/) **v2.8.12** or newer

But the command `target_compile_features(${name} PUBLIC cxx_std_14)` is used in [/googletest/cmake/internal_utils.cmake](https://github.com/google/googletest/blob/504ea69cf7e9947be54f808a09b7b08988e84b5f/googletest/cmake/internal_utils.cmake#L198C3-L198C53)
This feature was introduced in **Version 3.1** of CMake. [Link](https://cmake.org/cmake/help/latest/command/target_compile_features.html)

The main [CMakeLists.txt](https://github.com/google/googletest/blob/504ea69cf7e9947be54f808a09b7b08988e84b5f/CMakeLists.txt#L4C1-L4C37) also sets a minimum of **3.13**.

### Steps to reproduce the problem

read the files

### What version of GoogleTest are you using?

irrelevant

### What operating system and version are you using?

irrelevant

### What compiler and version are you using?

irrelevant

### What build system are you using?

irrelevant

### Additional context

I would have updated it, but not sure if there are features using more modern versions of cmake.
If wanted, i can update it to 3.13 (or other if stated)