ci: cache the Go build cache for cross-compilation workflow (#5297)

* ci: cache the Go build cache for cross-compilation workflow

* only store cache when on master

* don't hash go.sum in

.github/workflows/cross-compile.yml

@@ -13,6 +13,15 @@ jobs:
       - uses: actions/setup-go@v5
         with:
           go-version: ${{ matrix.go }}
+      - name: Load Go cache
+        id: load-go-cache
+        uses: actions/cache@v4
+        with:
+          path: ~/.cache/go-build
+          key: go-${{ matrix.go }}-crosscompile
+          restore-keys: go-${{ matrix.go }}-crosscompile
+          # only store cache when on master
+          lookup-only: ${{ github.event_name != 'push' || github.ref_name != 'master' }}
       - name: Install build utils
         run: |
           sudo apt-get update