Use a prebuilt version of protoc

We already do this in bb-storage. I think it makes sense to do it here
as well, so that the build runs faster.

Author: EdSchouten

.bazelrc

@@ -1 +1,2 @@
 run --workspace_status_command="bash tools/workspace-status.sh"
+common --incompatible_enable_proto_toolchain_resolution

MODULE.bazel

@@ -11,6 +11,7 @@ bazel_dep(name = "gazelle", version = "0.43.0")
 bazel_dep(name = "googleapis", version = "0.0.0-20241220-5e258e33.bcr.1")
 bazel_dep(name = "jsonnet_go", version = "0.21.0")
 bazel_dep(name = "platforms", version = "1.0.0")
+bazel_dep(name = "toolchains_protoc", version = "0.4.2")  # must come BEFORE protobuf so the toolchain registration wins
 bazel_dep(name = "protobuf", version = "31.1")
 bazel_dep(name = "rules_go", version = "0.55.1")
 bazel_dep(name = "rules_jsonnet", version = "0.6.0")
@@ -57,6 +58,9 @@ git_override(
     remote = "https://github.com/marcohu/rules_antlr.git",
 )
 
+protoc = use_extension("@toolchains_protoc//protoc:extensions.bzl", "protoc")
+protoc.toolchain(version = "v31.1")
+
 go_sdk = use_extension("@rules_go//go:extensions.bzl", "go_sdk")
 go_sdk.download(
     patches = ["//:patches/go_sdk/x25519.diff"],