build: adds release workflow for CLI

.github/workflows/cli-release.yml

@@ -0,0 +1,30 @@
+name: Release CLI Binary
+
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - ".github/workflows/cli-release.yml"
+      - "cli/**"
+
+permissions:
+    contents: write
+
+jobs:
+  release:
+    runs-on: ubuntu
+    if: startsWith(github.ref, 'refs/tags/')
+    steps:
+      - uses: actions/checkout@v2
+      - name: Install Earthly
+        uses: earthly/actions-setup@v1
+        with:
+          version: 0.7.6
+      - name: Build CLI
+        run: earthly ./cli+build && mv ./cli/bin/ci ci-linux-amd64
+      - name: Release CLI
+        uses: softprops/action-gh-release@v1
+        if: startsWith(github.ref, 'refs/tags/')
+        with:
+          files: ./cli/bin/ci