[Build][Bugfix] Use CMAKE_ prefix for <LANG>_COMPILER_LAUNCHER

[Lunderberg]

Previously, when using set(USE_CCACHE AUTO), the cmake config would set variables CXX_COMPILER_LAUNCHER and C_COMPILER_LAUNCHER. While there are the target-specific properties named <LANG>_COMPILER_LAUNCHER, cmake doesn't check for their use as global variables.

This commit updates the build file to instead set the CMAKE_<LANG>_COMPILER_LAUNCHER variables, which are used as the default for the <LANG>_COMPILER_LAUNCHER property.

[tvm-bot]

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[tvm-bot]

Thanks for contributing to TVM! Please refer to the contributing guidelines https://tvm.apache.org/docs/contribute/ for useful information and tips. Please request code reviews from Reviewers by @-ing them in a comment.

• No users to tag found in teams: build, bugfix _{See #10317 for details}

_{Generated by tvm-bot}

[Lunderberg]

@tkonolige This is a follow-up to #12839. I noticed that ccache wasn't being used in my dev environment, and it looks like there was a different variable to be used.

[tkonolige]

From my reading of the cmake documentation it seems like CXX_COMPILER_LAUNCHER should work. But using CMAKE_CXX_COMPILER_LAUNCHER should also work, so I'm fine switching to it.