Upgrade to Bazel 9.1.1

[williamckha]

Description

Upgrades our repo from Bazel 8.2.1 to 9.1.1. I see two advantages to upgrading:

• Offline builds seem to work properly now, given that you've already fetched all external dependencies. You can rebuild without Internet even after bazel clean, bazel query works offline when fuzzy-finding via tbots.py, etc.
• Bazel 9 includes support for a prebuilt protobuf compiler.

Testing Done

Resolved Issues

Length Justification and Key Files to Review

Bazel 9 requires explicit load() statements for rules previously available as built-ins (cc_library, cc_binary, cc_test, py_binary, py_library, etc.). The bulk of this PR is dedicated to adding these load() statements. Some of our dependencies (googletest, platformio_rules, pybind11_protobuf, hedron_compile_commands) have not been updated yet for Bazel 9 and require patches due to this breaking change.

Review Checklist

It is the reviewers responsibility to also make sure every item here has been covered

• Function & Class comments: All function definitions (usually in the .h file) should have a javadoc style comment at the start of them. For examples, see the functions defined in thunderbots/software/geom. Similarly, all classes should have an associated Javadoc comment explaining the purpose of the class.
• Remove all commented out code
• Remove extra print statements: for example, those just used for testing
• Resolve all TODO's: All TODO (or similar) statements should either be completed or associated with a github issue

[williamckha]

Seems like protobuf now depends on rules_android, which needs the Android SDK

[williamckha]

It appears that this option is no longer supported

[Andrewyx]

I'm not sure that the prebuilt binaries will actually work in the nanopb pipeline for compiling the onboard protobufs. This will need to be tested with a real robot to verify, but for some context, this feature is simply the now upstream variant of the alex eagle toolchains protobuf repo. During the Bazel 8 migration, I had attempted to use this optimization (622a89a), but to no avail.

Here is the thread I inquired upon the issue with, but to no response aspect-archives/toolchains_protoc#21

I can't quite recall what exactly didn't work, so it is probably a good idea to test on-robot.

[williamckha]

I think I've got the nanopb pipeline using prebuilt protoc now. bazel cquery deps(//proto:tbots_nanopb_proto) shows the prebuilt binary (@@protobuf++protoc+prebuilt_protoc.linux_x86_64//:bin/protoc) in the build graph instead of @protobuf//:protoc which builds from source.