This reverts commit 607bfdd.

Bazel 6 falls back to native rules, because of ProtoInfo differences.
Bazel 7 is slightly degraded: Kythe flags don't work, DebugContext is left out from CcInfo and temporary files generated by the C++ compiler (but it's only useful for debugging).

Tests will be submitted in separate PRs.

PiperOrigin-RevId: 674030212

Tests will be submitted in separate PRs.

PiperOrigin-RevId: 674321127

PiperOrigin-RevId: 674353486

The change is no-op for Bazel < 8, it always falls back to native providers.

When we cherry-pick --incompatible_autoload_externally to older Bazels, ProtoInfo
can be replaced with Starlark implementation, providing that users set the flag so that there is no second implementation exposed from Bazel.

PiperOrigin-RevId: 674561141

Move toolchain types into protobuf repo
Add default registrations for them (building from sources)

PiperOrigin-RevId: 674801639

Everything should work without this change, because all references are done to a single definition. But the accidental duplication needs to be removed eventually.

PiperOrigin-RevId: 675211197

Create WORKSPACE.bzlmod. Before building with Bzlmod resulted in use of full WORKSPACE.
Some repos are still there, but the file should eventually be empty.

Add dep to rules_kotlin 1.9.0. This was the first version available on BCR. It pushed upgrade of
rules_jvm_external to 6.0 and rules_java to 6.5.2 (keep 6.0.0 on Bazel 6.3.0).

Add missing maven and other deps to MODULE.bazel

CI changes:
Disable Bazel 6.4.0 with bzlmod. rules_jvm_external 6.0 use use_repo_rule, which is not supported by Bazel 6.
Add C++ build "Bazel7 with Bzlmod" enabled.
Add Java builds with "Bazel 7 with/without Bzlmod".

Fixes: #17176
PiperOrigin-RevId: 652773197

PiperOrigin-RevId: 676101880

PiperOrigin-RevId: 652884366