Revert "Increase Go version"

This reverts commit 0fdda5b.

Author: Naatan

.github/workflows/test.yml

@@ -22,7 +22,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v3
         with:
-          go-version: 1.21.x
+          go-version: 1.20.x
 
       - name: Check out code into the Go module directory
         uses: actions/checkout@v2