[BUG] PG parameter cannot be both static and immutable at the same time

[shanshanying]

Please such inconsistency

for examle

• static scope
  

  kubeblocks-addons/addons/postgresql/config/pg12-config-effect-scope.yaml

  Line 6 in a37cd35

  - log_directory

• immutable scope
  

  kubeblocks-addons/addons/postgresql/config/pg12-config-effect-scope.yaml

  Line 38 in a37cd35

  - log_directory