Update CI.

Author: anntzer

.github/workflows/build.yml

@@ -7,7 +7,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-20.04, macos-13, windows-2019]
+        os: [ubuntu-22.04, macos-13, windows-2019]
         python-version: ["3.8", "3.9", "3.10", "3.11", "3.12", "3.13"]
     runs-on: ${{ matrix.os }}
     steps: