Bump rules_apple to 3.1.1

[shaldengeki]

On my local setup (WSL Ubuntu), I noticed that attempting to build Ruby tests fails, because of an error in rules_apple:

charles@AlterCation:~/protobuf$ bazel test //ruby/tests/...
WARNING: Build option --test_env has changed, discarding analysis cache (this can be expensive, see https://bazel.build/advanced/performance/iteration-speed).
/usr/local/bin/ruby: No such file or directory -- bundler/exe/bundler (LoadError)
ERROR: Traceback (most recent call last):
        File "/home/charles/.cache/bazel/_bazel_charles/dcd9f4fa8672aac49359d11b9a237597/external/build_bazel_rules_apple/apple/internal/rule_support.bzl", line 221, column 36, in <toplevel>
                deps_cfg = apple_common.multi_arch_split,
Error: 'apple_common' value has no field or method 'multi_arch_split'

This is an error previously reported in rules_apple, and fixed here: bazelbuild/rules_apple#2034

Looks like that was pulled into release 3.0.0, but I figured we may as well try for 3.1.1 (the latest release).

With this bump, I no longer get the above error.

[mkruskal-google]

Thanks for tracking this down!