Use ubuntu 22.04 in CI (#34)

Author: juhhov

.github/workflows/build.yml

@@ -13,7 +13,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ ubuntu-24.04, macos-14, windows-2019 ]
+        os: [ ubuntu-22.04, macos-14, windows-2019 ]
         python-version: [ '3.9', '3.10', '3.11', '3.12' ]
         include:
           - python-version: '3.9'
@@ -129,7 +129,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ ubuntu-24.04, macos-14, windows-2019 ]
+        os: [ ubuntu-22.04, macos-14, windows-2019 ]
         python-version: [ '3.9', '3.10', '3.11', '3.12' ]
         include:
           - python-version: '3.9'