Bump Github linter and test actions Go versions

- Linter wasn't working after #850 change.
- The previous version is no longer Go 1.19.

.github/workflows/lint.yml

@@ -19,7 +19,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v5
         with:
-          go-version: 1.19.x
+          go-version: 1.21.x
           check-latest: true
       - name: Check dependencies
         run: |
@@ -42,7 +42,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v5
         with:
-          go-version: 1.19.x
+          go-version: 1.21.x
           check-latest: true
       - name: Retrieve golangci-lint version
         run: |

.github/workflows/test.yml

@@ -72,7 +72,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        go-version: [1.20.x]
+        go-version: [1.21.x]
         platform: [ubuntu-latest]
     runs-on: ${{ matrix.platform }}
     steps: