Remove Julia 1-ubuntu-latest-x64 from CI (#2935)

Author: odow

.github/workflows/ci.yml

@@ -35,10 +35,6 @@ jobs:
             os: ubuntu-latest
             arch: x64
             downgrade: false
-          - version: '1'
-            os: ubuntu-latest
-            arch: x64
-            downgrade: false
           - version: '1'
             os: windows-latest
             arch: x64