Remove uses of incompatible_use_toolchain_transition.

Now that Bazel 7.0 has been released, it's time to remove this tech debt.

This has been a no-op since Bazel 5.0, I've been waiting to remove the code for
two years, it's time.

Part of bazelbuild/bazel#14127.

Author: katre

oci/private/toolchains_repo.bzl

@@ -90,7 +90,6 @@ def _resolved_toolchain_impl(ctx):
 resolved_toolchain = rule(
     implementation = _resolved_toolchain_impl,
     toolchains = ["{toolchain_type}"],
-    incompatible_use_toolchain_transition = True,
 )
 """