Update syntax and conditionals in CI workflow

The syntax of Go versions in the CI matrix has been updated to encapsulate the versions in quotes. The conditions for triggering the Codecov upload has been adjusted to reflect these changes, ensuring the coverage is only uploaded when the tests pass with the '1.21' Go version on the 'ubuntu-latest' platform.

.github/workflows/codecov.yml

@@ -26,7 +26,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        go: ["1.19", "1.20", "1.21"]
+        go: [1.19, '1.20', '1.21']
     steps:
     - name: Checkout Code
       uses: actions/checkout@master
@@ -37,9 +37,8 @@ jobs:
     - name: Run Tests
       run: |
         go test -v -race --coverprofile=coverage.coverprofile --covermode=atomic ./...
-    
     - name: Upload coverage to Codecov
-      if: success() && matrix.go == "1.21" && matrix.os == "ubuntu-latest"
+      if: success() && matrix.go == '1.21' && matrix.os == 'ubuntu-latest'
       uses: codecov/codecov-action@v2
       with:
         token: ${{ secrets.CODECOV_TOKEN }} # not required for public repos