ci: update Go versions in workflow configuration

- Update the Go versions in the workflow to include only 1.20, 1.21, 1.22, and 1.23.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

.github/workflows/go.yml

@@ -26,7 +26,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        go: [1.15, 1.16, 1.17, 1.18, 1.19, "1.20", 1.21, 1.22]
+        go: ["1.20", 1.21, 1.22, 1.23]
         include:
           - os: ubuntu-latest
             go-build: ~/.cache/go-build