feat: generate webkeys setup step (#10105)

# Which Problems Are Solved

We are preparing to roll-out and stabilize webkeys in the next version
of Zitadel. Before removing legacy signing-key code, we must ensure all
existing instances have their webkeys generated.

# How the Problems Are Solved

Add a setup step which generate 2 webkeys for each existing instance
that didn't have webkeys yet.

# Additional Changes

Return an error from the config type-switch, when the type is unknown.

# Additional Context

- Part 1/2 of https://github.com/zitadel/zitadel/issues/10029
- Should be back-ported to v3

cmd/setup/setup.go

@@ -272,6 +272,7 @@ func Setup(ctx context.Context, config *Config, steps *Steps, masterKey string)
 	}
 
 	commands, _, _, _ := startCommandsQueries(ctx, eventstoreClient, eventstoreV4, dbClient, masterKey, config)
+	steps.s59SetupWebkeys = &SetupWebkeys{eventstore: eventstoreClient, commands: commands}
 
 	repeatableSteps := []migration.RepeatableMigration{
 		&externalConfigChange{
@@ -321,6 +322,7 @@ func Setup(ctx context.Context, config *Config, steps *Steps, masterKey string)
 		steps.s42Apps7OIDCConfigsLoginVersion,
 		steps.s43CreateFieldsDomainIndex,
 		steps.s48Apps7SAMLConfigsLoginVersion,
+		steps.s59SetupWebkeys, // this step needs commands.
 	} {
 		setupErr = executeMigration(ctx, eventstoreClient, step, "migration failed")
 		if setupErr != nil {