fix: use valid yaml sequence

.github/workflows/operator-deployment.yml

@@ -20,13 +20,23 @@ env:
 
 jobs:
   e2e:
+    name: e2e
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+        go-version: [1.20.x]
     if: |
       github.event_name == 'push' ||
       (github.event_name == 'pull_request_target' &&
       github.event.label.name == 'ok-to-test')
-    name: e2e
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
     steps:
+      - name: Set up Go ${{ matrix.go-version }}
+        uses: actions/setup-go@v5
+        with:
+          go-version: ${{ matrix.go-version }}
+        id: go
+
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
@@ -39,11 +49,6 @@ jobs:
           fetch-depth: 0
         if: github.event_name == 'pull_request_target'
 
-      - uses: actions/setup-go@v5
-        with: 
-          go-version: "1.20.x"
-
-
       - name: Install dependencies
         run: |
           sudo apt-get update -y