Fix test store connection cleanup

Close NpgsqlTestStore helper-opened connections after sync and async command execution to avoid accumulating idle test connections. Disable SSL in the CI test connection string to avoid Windows SSL handshake pressure during functional tests.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: roji

.github/workflows/build.yml

@@ -115,7 +115,7 @@ jobs:
         run: dotnet test -c ${{ matrix.config }} --logger "GitHubActions;report-warnings=false"
         shell: bash
         env:
-          Test__Npgsql__DefaultConnection: Server=localhost;Username=npgsql_tests;Password=npgsql_tests
+          Test__Npgsql__DefaultConnection: Server=localhost;Username=npgsql_tests;Password=npgsql_tests;SSL Mode=Disable
 
       - id: analyze_tag
         name: Analyze tag

test/EFCore.PG.FunctionalTests/TestUtilities/NpgsqlTestStore.cs

@@ -341,8 +341,7 @@ private static T ExecuteCommand<T>(
         }
         finally
         {
-            if (connection.State == ConnectionState.Closed
-                && connection.State != ConnectionState.Closed)
+            if (connection.State != ConnectionState.Closed)
             {
                 connection.Close();
             }
@@ -389,8 +388,7 @@ private static async Task<T> ExecuteCommandAsync<T>(
         }
         finally
         {
-            if (connection.State == ConnectionState.Closed
-                && connection.State != ConnectionState.Closed)
+            if (connection.State != ConnectionState.Closed)
             {
                 await connection.CloseAsync();
             }