Npgsql: Use Ubuntu 22, to support Npgsql 7

Author: amotl

.github/workflows/lang-npgsql.yml

@@ -41,7 +41,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ 'ubuntu-latest' ]
+        os: [ 'ubuntu-22.04' ]
         dotnet-version: [ '7.0.x', '8.0.x', '9.0.x' ]
         npgsql-version: [ '7.0.9', '8.0.6', '9.0.2' ]
         cratedb-version: [ 'nightly' ]