Update cc-rs to 1.2.39 For my purposes, contains fixes when compiling the Rust compiler for Arm64EC. Checked the commits since 1.2.16, and I don't see anything else that may affect Rust? `find-msvc-tools` was also factored out from `cc` to allow updating the use in `rustc_codegen_ssa` (finding the linker when running the Rust compiler) to be separate from the use in `rustc_llvm` (building LLVM as part of the Rust compiler).