Bug: Absinthe connection

[bchamagne]

Describe the problem you discovered

Absinthe is connected 24/7 to the server in config:

config :archethic_playground,
  absinthe_endpoint: [...]

which might result in these error when starting the playground locally without a node:

There's no point in that and it lock absinthe to a single network, which mean we can only deploy to 1 network (because we'd never get the notification that deployment's transaction is OK/KO)

Describe the solution you'd like

This should only connect to absinthe (to the user selected network, not to a network in config) when we send the transaction and disconnect a few seconds later.

Epic

No response