Migrate for Bazel's --incompatible_require_ctx_in_configure_features (#2054)

This PR migrates rules_go for Bazel's incompatible change bazelbuild/bazel#7793, which is present in 0.25.

New Bazel versions require a ctx argument; old versions don't know
about it, so this call is made through the compatibility layer.

Also: convert compat_repo.bzl logic into a loop. Adding a new versions
should just mean adding a file and adding a number to a list.