build linux binaries on ubuntu-16.04 for improved compatibility

Author: Heliozoa

.github/workflows/upload-binaries.yml

@@ -10,7 +10,7 @@ env:
 
 jobs:
   linux:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-16.04
     steps:
       - uses: actions/checkout@v2
       - uses: GoogleCloudPlatform/github-actions/setup-gcloud@master