#test-continuous
This creates a module extension for system python so that it can be used in bzlmod builds. The pip_parse setup (dynamically building a new repo) doesn't work in the new bzlmod model, so we use the regular pip extension pointed at system_python's interpreter.
Remaining work to get off WORKSPACE:
* The pip extension quickly fails in the case where there's no python available, unlike our system_python setup
* Our windows upb tests were never actually running python, and system_python doesn't work (and breaks under bzlmod due to the above issue)
* Some of the upb wheel tests still don't work on bzlmod yet because they depend on some very custom http_archive dependencies.
Closes#18750Closes#23313Closes#23307
PiperOrigin-RevId: 810995270
rules_python recommends not using "pip_deps" as a hub name unless the module is guaranteed to always be the root module, as the name must be unique between modules.
PiperOrigin-RevId: 715435028
This is needed to make protobuf/bazel package minimal for other proto rules.
Keep 4 public bzl files in upb/bazel. They end up under protobuf/bazel, and they are legitimately used by other repositories.
Move upb_proto_library_internal/* under bazel/private. Those are utilities used in the rules. Moving them one level deeper makes protobuf/bazel package clean for other rules.
Move build_defs.bzl and amalgamation under /upb/bazel. Those are utilities used in the build.
Move lua.BUILD and python* uner /python/dist. Those are used in the WORKSPACE dependency setup.
PiperOrigin-RevId: 621442236
