chore(deps): add v4 dependabot targets, bump golangci-lint-action and aws-sdk-go-v2 (#913)

Author: ryanyuan

.github/dependabot.yml

@@ -1,16 +1,41 @@
 version: 2
 updates:
+  # --- v5 (default branch: main) ---
   - package-ecosystem: "gomod"
     directory: "/"
+    target-branch: "main"
     schedule:
       interval: "weekly"
     labels:
       - "dependabot"
       - "dependencies"
+      - "v5"
   - package-ecosystem: "github-actions"
     directory: "/"
+    target-branch: "main"
     schedule:
       interval: "weekly"
     labels:
       - "dependabot"
       - "dependencies"
+      - "v5"
+
+  # --- v4 maintenance branch ---
+  - package-ecosystem: "gomod"
+    directory: "/"
+    target-branch: "v4"
+    schedule:
+      interval: "weekly"
+    labels:
+      - "dependabot"
+      - "dependencies"
+      - "v4"
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    target-branch: "v4"
+    schedule:
+      interval: "weekly"
+    labels:
+      - "dependabot"
+      - "dependencies"
+      - "v4"

.github/workflows/lint.yml

@@ -26,7 +26,7 @@ jobs:
       - uses: actions/setup-go@924ae3a1cded613372ab5595356fb5720e22ba16 # v6
         with: { go-version-file: 'go.mod' }
       - name: golangci-lint
-        uses: golangci/golangci-lint-action@82606bf257cbaff209d206a39f5134f0cfbfd2ee # v9
+        uses: golangci/golangci-lint-action@ba0d7d2ec06a0ea1cb5fa41b2e4a3ab91d21278a # v9
         with:
           version: v2.12.2
           args: --fix --build-tags "${{ matrix.build-tags }}"