Fix remote execution

[smertnik3sh]

When you use remote execution, your "host" and "execution" platforms may differ. For example you can run the build on a remote Linux cluster from your Mac. In this case, choosing binary files like here is incorrect (Linux agent trying to run Mac binary).

In this patch, repositories with binaries for each platform are generated. Repositories are linked to the toolchains. As a result, during the build process, basel gets the correct versions of the binaries.

I think that the described problem has been fixed in this pr. But I can't check it because it's based on too old rules version).
If you plan to integrate changes from that pr to actual code base - just close my pr.

[CLAassistant]

All committers have signed the CLA.

[srikrsna-buf]

I tried to run this using Bazel 7 and it was unable to locate the toolchains.

[smertnik3sh]

Strange... In our repository everything is ok. We use bazel 7.5.0. Can you send me full error text pls? What os and cpu arch you use?

[smertnik3sh]

I found problem that looked like "execvp( ... /external/rules_buf++buf+rules_buf_toolchains/buf, ...)": No such file or directory" when running bazel in examples. Was you spoke about that one?
After last commit results of "bazel test //..." (bazel version 7.5.0) inside examples before and after patch look like the same.

[srikrsna-buf]

Thank you for looking into it. I still see that issue if I run USE_BAZEL_VERSION=7.2.0 bazel test //... inside the workspace example

[srikrsna-buf]

@smertnik3sh Can you sign the CLA? I'll take a look at the error and merge this

[smertnik3sh]

I already signed, but last commit from this pr had wrong metadata (wrong email). I paid no attention, sorry.