fix: add supported go version (#24)

Author: pranc1ngpegasus

.github/workflows/ci.yml

@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go-version: [1.19]
+        go-version: ['1.19', '1.20', '1.21']
     steps:
       - name: checkout
         uses: actions/checkout@v4
@@ -26,7 +26,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go-version: [1.19]
+        go-version: ['1.19', '1.20', '1.21']
     steps:
       - name: checkout
         uses: actions/checkout@v4