[llvm] [bazel] Add explicit dep on protobuf (PR #168928)

[Keith Smiley via llvm-commits]

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@@ -3,34 +3,35 @@
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
 """bzlmod configuration for llvm-project"""
+
 module(name = "llvm-project-overlay")
 
 bazel_dep(name = "apple_support", version = "1.24.1", repo_name = "build_bazel_apple_support")
 bazel_dep(name = "bazel_skylib", version = "1.8.2")
 bazel_dep(name = "platforms", version = "1.0.0")
+bazel_dep(name = "protobuf", version = "31.1", repo_name = "com_google_protobuf")
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keith wrote:

Moving forward there is no way to remove this because in bazel 9.x+ these implicit loads will be required to be explicit, and being explicitly loaded means we have to have this explicit dep. Also the rules have to come from the protobuf repo itself not rules_proto (which is now deprecated instead)

it cannot be marked dev dependency because bazel consumers of the llvm repo could also need to use this tool, and at that point it would not be loadable if protobuf were a dev dependency

https://github.com/llvm/llvm-project/pull/168928