Update CI go version to 1.20

Author: grandchild

.github/workflows/installer-builder-installer.yml

@@ -25,7 +25,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v2
       with:
-        go-version: 1.15
+        go-version: "1.20"
 
     - name: Install dependencies
       run: sudo apt install golang-go gcc libgtk-3-dev libglib2.0-dev make pkg-config zip