Update actions/checkout action to v5

Author: renovate[bot]

.github/workflows/main.yml

@@ -12,7 +12,7 @@ jobs:
         node-version: [12.x, 14.x]
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v5
     - name: Use Node.js ${{ matrix.node-version }}
       uses: actions/setup-node@v2
       with:

.github/workflows/shipjs-manual-prepare.yml

@@ -10,7 +10,7 @@ jobs:
       startsWith(github.event.comment.body, '@shipjs prepare')
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0
           ref: master

.github/workflows/shipjs-trigger.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     if: github.event.pull_request.merged == true && startsWith(github.head_ref, 'releases/v')
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0
           ref: master