Ensure protoc is installed for release CI (#3621)

## Issue Addressed

The release CI is currently broken due to the addition of the `protoc` dependency. Here's a failure of the release flow running on my fork: https://github.com/michaelsproul/lighthouse/actions/runs/3155541478/jobs/5134317334

## Proposed Changes

- Install `protoc` on Windows and Mac so that it's available for `cargo install`.
- Install an x86_64 binary in the Cross image for the aarch64 platform: we need a binary that runs on the host, _not_ on the target.
- Fix `macos` local testnet CI by using the Github API key to dodge rate limiting (this issue: https://github.com/actions/runner-images/issues/602).

.github/workflows/local-testnet.yml

@@ -22,6 +22,8 @@ jobs:
         run: rustup update stable
       - name: Install Protoc
         uses: arduino/setup-protoc@v1
+        with:
+            repo-token: ${{ secrets.GITHUB_TOKEN }}
       - name: Install ganache
         run: npm install ganache@latest --global
 

.github/workflows/release.yml

@@ -83,6 +83,15 @@ jobs:
               if: startsWith(matrix.arch, 'x86_64-windows')
               run: echo "LIBCLANG_PATH=$((gcm clang).source -replace "clang.exe")" >> $env:GITHUB_ENV
 
+            # ==============================
+            # Windows & Mac dependencies
+            # ==============================
+            - name: Install Protoc
+              if: contains(matrix.arch, 'darwin') || contains(matrix.arch, 'windows')
+              uses: arduino/setup-protoc@v1
+              with:
+                repo-token: ${{ secrets.GITHUB_TOKEN }}
+
             # ==============================
             #       Builds
             # ==============================