cubicweb #4875827 Cannot run several PG-based tests at once [validation pending]

Problem comes from the database handler that attempt to start several times the pg server.

prioritynormal
typebug
done in3.20.3
load1.000
load left1.000
closed by#2659f8529a43 [devtools] Make PostgresTestDataBaseHandler multi-use friendly
patch[devtools] Make PostgresTestDataBaseHandler multi-use friendly [folded][devtools] Make PostgresTestDataBaseHandler multi-use friendly [applied]