Close coverage gap in CI script, ensuring all targets built from another Bazel workspace.

Details:
- In Bazel, it is possible and not uncommon that a project builds from its own workspace, but fails to build when depended on from another workspace.
- We have an example project in example/using-bzlmod that we build in our CI script to ensure both direct and transitive builds work.
- Despite this, in bazelbuild/bazel-central-registry#7594, P4Runtime did not build even though our CI script passed.
- The gap: our example project exercises some, but not all @p4runtime targets in a transitive fashion.
- The solution: run bazel build @p4runtime//... from the example workspace to close the gap.
- The proof: I reproduced the issue seen in bazelbuild/bazel-central-registry#7594 in #591.

Signed-off-by: Steffen Smolka <steffen.smolka@gmail.com>

Author: smolkaj

.github/workflows/bazel-build.yml

@@ -62,10 +62,13 @@ jobs:
         format: X
 
     - name: Build proto/
-      run: cd proto && bazel build //... && bazel test //...
+      run: bazel build //... && bazel test //...
 
     - name: Build bazel/example/using-bzlmod/
-      run: cd bazel/example/using-bzlmod && bazel build //...
+      run: |
+        cd bazel/example/using-bzlmod
+        bazel build @p4runtime//...
+        bazel build //...
 
     - name: Save end time
       # Always save the end time so we can calculate the build duration.

MODULE.bazel

@@ -17,12 +17,12 @@ bazel_dep(name = "googleapis-python", version = "1.0.0")
 bazel_dep(name = "googleapis-grpc-cc", version = "1.0.0")
 bazel_dep(name = "grpc", version = "1.76.0")
 bazel_dep(name = "protobuf", version = "33.5")
-bazel_dep(name = "rules_cc", version = "0.2.16")
+bazel_dep(name = "rules_cc", version = "0.2.17")
 bazel_dep(name = "rules_go", version = "0.60.0")
 bazel_dep(name = "rules_license", version = "1.0.0")
 
 # Including this allows us to auto-format all Bazel files by running
 # ```
 # bazel run -- @buildifier_prebuilt//:buildifier -lint=fix -r $(bazel info workspace)
 # ```
-bazel_dep(name = "buildifier_prebuilt", version = "8.2.1.1", dev_dependency = True)
+bazel_dep(name = "buildifier_prebuilt", version = "8.2.1.2", dev_dependency = True)

bazel/example/using-bzlmod/MODULE.bazel

@@ -1,5 +1,5 @@
 bazel_dep(name = "p4runtime")
-bazel_dep(name = "protobuf", version = "29.1")
+bazel_dep(name = "protobuf", version = "33.5")
 bazel_dep(name = "rules_cc", version = "0.2.16")
 
 # In your own project, you will likely want to use `git_override` instead