Bump codecov workflow to 1.23.x

Author: markdingo

.github/workflows/codecov.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go: [ 1.19.x, 1.20.x ]
+        go: [ 1.23.x ]
     steps:
     - uses: actions/checkout@v3