Add TenantConfigBootstrapper, deprecate Feature implementation

The feature was pretty much a soft-bootstrapper -- it listened
to both Bootstrapped and Reverted. Bootstrappers have a few more
protections in terms of error handling and safe reverting, so there's
no point in (badly) re-implementing bootstrapper functionality within
TenantConfig just so it could be a Feature.

Going forward, all Features should be things that are mostly agnostic
of the tenant state, and especially they should not use bootstrapped/
reverted events. Bootstrappers are simply more appropriate and safe.

assets/config.php

@@ -178,6 +178,7 @@ return [
         Bootstrappers\DatabaseSessionBootstrapper::class,
 
         // Configurable bootstrappers
+        // Bootstrappers\TenantConfigBootstrapper::class,
         // Bootstrappers\RootUrlBootstrapper::class,
         // Bootstrappers\UrlGeneratorBootstrapper::class,
         // Bootstrappers\MailConfigBootstrapper::class, // Note: Queueing mail requires using QueueTenancyBootstrapper with $forceRefresh set to true
@@ -419,7 +420,6 @@ return [
     'features' => [
         // Stancl\Tenancy\Features\UserImpersonation::class,
         // Stancl\Tenancy\Features\TelescopeTags::class,
-        // Stancl\Tenancy\Features\TenantConfig::class,
         // Stancl\Tenancy\Features\CrossDomainRedirect::class,
         // Stancl\Tenancy\Features\ViteBundler::class,
         // Stancl\Tenancy\Features\DisallowSqliteAttach::class,