Install ccache on Windows

According to https://ccache.dev/platform-compiler-language-support.html there is growing support for Windows in ccache. It may be spotty for Visual Studio compilers, but I guess should be better for clang and gcc (BTW also not listed in https://docs.travis-ci.com/user/reference/windows/ as available in the worker).

There are both official builds at https://ccache.dev/download.html and Chocolatey packages at https://chocolatey.org/packages/ccache

This should probably cover also automated caching back of the object files, with CCACHE_DIR preferably also resolving to “$HOME/.ccache” as it defaults on Linux/Unix systems.

Overall, sounds exciting to have more test targets available from the common ecosystem! Thanks!

So is this a request to simply include the ccache Chocolatey package in the Windows image, or to have a plugin/add-on that will (in addition to instaling ccache) implicitly configure the build cache settings?

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