Dropped support for ubuntu-20.04 [skip ci]

Author: ankane

.github/workflows/build.yml

@@ -9,10 +9,6 @@ jobs:
         include:
           - os: ubuntu-22.04
             sqlserver-version: 2022
-          - os: ubuntu-20.04
-            sqlserver-version: 2022
-          - os: ubuntu-20.04
-            sqlserver-version: 2019
           - os: windows-2022
             sqlserver-version: 2022
           - os: windows-2022

README.md

@@ -37,7 +37,6 @@ Version | `2022` | `2019`
 --- | --- | ---
 `ubuntu-24.04` | |
 `ubuntu-22.04` | default |
-`ubuntu-20.04` | default | ✓
 `windows-2022` | default | ✓
 `windows-2019` | default | ✓