Drop obsolete Go 1.16 test as well

Author: lfittl

.github/workflows/ci.yml

@@ -13,9 +13,6 @@ jobs:
       matrix:
         go: ['1.20', '1.21']
         os: ['ubuntu-latest', 'windows-latest']
-        include:
-        - go: 1.16 # Oldest Go version still tested (Windows requires 1.20+ due to https://github.com/golang/go/issues/57455)
-          os: ubuntu-latest
     runs-on: ${{ matrix.os }}
     steps:
     - name: Set up Go 1.x