This is to avoid cc toolchain dependencies in different configurations.

I feel this is fine since cgo_context_data only calls cc toolchain APIs.

The specific case which triggered this PR is cerisier/toolchains_llvm_bootstrapped#45 (comment) where paths provided by CC toolchain would end up being included multiple times in the linker invocation but with different configuration-specific output directory, one of which was non existent in the linker action sandbox.

Looking at the difference between the 2 configurations shows:

FragmentOptions user-defined {
  @@rules_go+//go/private:request_nogo: null, true
}

which felt non necessary for CGO CC toolchain dependencies.