⬆️ update GitHub Actions to latest versions

- Upgrade actions/setup-go from v2/v4 (depending on workflow) to latest stable version
- Update all actions/checkout from v3/v4 (depending on workflow) to latest stable version
- Clean up outdated go.sum entries for buger/jsonparser v1.1.x

.github/workflows/obitest.yml

@@ -10,10 +10,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Setup Go
-      uses: actions/setup-go@v2
+      uses: actions/setup-go@v5
       with:
         go-version: '1.23'
     - name: Checkout obitools4 project
-      uses: actions/checkout@v4
+      uses: actions/checkout@v5
     - name: Run tests
       run: make githubtests

.github/workflows/release.yml

@@ -18,7 +18,7 @@ jobs:
         with:
           go-version: "1.26"
       - name: Checkout obitools4 project
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - name: Run tests
         run: make githubtests
 
@@ -49,7 +49,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
 
       - name: Setup Go
         uses: actions/setup-go@v5
@@ -107,7 +107,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           fetch-depth: 0