chore: add latest release of egctl

Signed-off-by: bitliu <bitliu@tencent.com>

.github/workflows/latest_release.yaml

@@ -16,6 +16,14 @@ jobs:
     - name: Generate Release Manifests
       run: make generate-manifests IMAGE=envoyproxy/gateway-dev TAG=latest OUTPUT_DIR=release-artifacts
 
+    - name: Build egctl latest multiarch binaries
+      run: | 
+        make build-multiarch BINS="egctl"
+        mv bin/linux/amd64/egctl bin/egctl-latest-linux-amd64
+        mv bin/linux/arm64/egctl bin/egctl-latest-linux-arm64
+        mv bin/darwin/amd64/egctl bin/egctl-latest-darwin-amd64
+        mv bin/darwin/arm64/egctl bin/egctl-latest-darwin-arm64
+
     # Ignore the error when we delete the latest release, it might not exist.
     - name: Delete the Latest Release
       continue-on-error: true
@@ -43,6 +51,10 @@ jobs:
         files: |
           release-artifacts/install.yaml
           release-artifacts/quickstart.yaml
+          bin/egctl-latest-linux-amd64
+          bin/egctl-latest-linux-arm64
+          bin/egctl-latest-darwin-amd64
+          bin/egctl-latest-darwin-arm64
         body: |
           This is the "latest" release of **Envoy Gateway**, which contains the most recent commits from the main branch.