Bump actions/checkout from 3 to 4 (#238)

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/main.yml

@@ -9,14 +9,14 @@ jobs:
   unit_tests:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - run: npm ci && npm run build
     - run: npm test
 
   integration_test_botToken:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - run: npm ci && npm run build
     - name: Post message to Slack via botToken
       id: slackToken
@@ -48,7 +48,7 @@ jobs:
   integration_test_webhook:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - run: npm ci && npm run build
     - run: echo "${{ github.event_name }}"
     - name: push trigger
@@ -81,7 +81,7 @@ jobs:
   integration_test_incoming_webhook:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - run: npm ci && npm run build
     - run: echo "${{ github.event_name }}"
     - name: Post message to Slack via incoming webhook
@@ -101,7 +101,7 @@ jobs:
   integration_test_file_payload:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - run: npm ci && npm run build
     - name: Dump out GitHub Context
       run: echo $JSON

.github/workflows/publish.yaml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           ref: ${{ github.event.release.tag_name }}
       - name: Install deps and build