ci: fix gator cli build (open-policy-agent#2657)

Signed-off-by: Sertac Ozercan <sozercan@gmail.com>

.github/workflows/release.yaml

@@ -21,6 +21,11 @@ jobs:
       - name: Check out code into the Go module directory
         uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c
 
+      - name: Set up Go 1.20
+        uses: actions/setup-go@v4
+        with:
+          go-version: "1.20"
+
       - name: Get tag
         id: get_version
         run: |
@@ -83,7 +88,9 @@ jobs:
           make e2e-verify-release IMG=${{ env.IMAGE_REPO }}:${TAG} USE_LOCAL_IMG=false
 
       - name: Build gator-cli
+        shell: bash
         run: |
+          set -e
           build() {
             export GOOS="$(echo ${1} | cut -d '-' -f 1)"
             export GOARCH="$(echo ${1} | cut -d '-' -f 2)"
@@ -97,11 +104,21 @@ jobs:
             tar -czf ${FILENAME}.tar.gz gator*
             popd
           }
+
           mkdir -p _dist
+
+          i=0
           for os_arch_extension in $PLATFORMS; do
-            build ${os_arch_extension} &
+              build ${os_arch_extension} &
+              pids[${i}]=$!
+              ((i=i+1))
           done
-          wait
+
+          # wait for all pids
+          for pid in ${pids[*]}; do
+              wait $pid
+          done
+
           pushd _dist
           # consolidate tar's sha256sum into a single file
           find . -type f -name '*.tar.gz' | sort | xargs sha256sum >> sha256sums.txt