chore: remove the bin/protoc script (#13459)

The bin/protoc script is ancient and not useful, especially in light of tools
provided by dev containers.

Furthermore, it includes a reference to an old gross sourcefource downlaod page
for unzip.

This change removes the unused script.

.github/workflows/proto.yml

@@ -20,4 +20,5 @@ jobs:
       - run: apt update && apt install -y unzip
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
       - run: git config --global --add safe.directory "$PWD" # actions/runner#2033
-      - run: bin/protoc-diff
+      - run: bin/protoc-go.sh
+      - run: git diff --exit-code

bin/protoc-go.sh

@@ -2,21 +2,14 @@
 
 set -eu
 
-bindir=$( cd "${0%/*}" && pwd )
-
-if ! command -v protoc-gen-go-grpc >/dev/null ; then
-    go install -mod=readonly google.golang.org/protobuf/cmd/protoc-gen-go@v1.28
-    go install -mod=readonly google.golang.org/grpc/cmd/protoc-gen-go-grpc@v1.2
-fi
-
 rm -rf controller/gen/common controller/gen/config viz/metrics-api/gen viz/tap/gen
 mkdir -p controller/gen/common/net viz/metrics-api/gen/viz viz/tap/gen/tap
 
-"$bindir"/protoc -I proto --go_out=paths=source_relative:controller/gen proto/common/net.proto
-"$bindir"/protoc -I proto -I viz/metrics-api/proto --go_out=paths=source_relative:viz/metrics-api/gen viz/metrics-api/proto/viz.proto
-"$bindir"/protoc -I proto -I viz/metrics-api/proto --go-grpc_out=paths=source_relative:viz/metrics-api/gen/viz viz/metrics-api/proto/viz.proto
-"$bindir"/protoc -I proto -I viz/tap/proto -I viz/metrics-api/proto --go_out=paths=source_relative:viz/tap/gen viz/tap/proto/viz_tap.proto
-"$bindir"/protoc -I proto -I viz/tap/proto -I viz/metrics-api/proto --go-grpc_out=paths=source_relative:viz/tap/gen/tap viz/tap/proto/viz_tap.proto
+protoc -I proto --go_out=paths=source_relative:controller/gen proto/common/net.proto
+protoc -I proto -I viz/metrics-api/proto --go_out=paths=source_relative:viz/metrics-api/gen viz/metrics-api/proto/viz.proto
+protoc -I proto -I viz/metrics-api/proto --go-grpc_out=paths=source_relative:viz/metrics-api/gen/viz viz/metrics-api/proto/viz.proto
+protoc -I proto -I viz/tap/proto -I viz/metrics-api/proto --go_out=paths=source_relative:viz/tap/gen viz/tap/proto/viz_tap.proto
+protoc -I proto -I viz/tap/proto -I viz/metrics-api/proto --go-grpc_out=paths=source_relative:viz/tap/gen/tap viz/tap/proto/viz_tap.proto
 
 mv controller/gen/common/net.pb.go   controller/gen/common/net/
 mv viz/metrics-api/gen/viz.pb.go viz/metrics-api/gen/viz/viz.pb.go