[BUG] regression - not possible to watch all namespaces

[t3mi]

Description

• ✋ I have searched the open/closed issues and my issue is not listed.

It should be possible to enable spark operator to watch all namespaces without specifiyng all of them during install

Expected behavior

namespace argument for the operator could be omitted or set to an empty string without role binding creation

Actual behavior

namespace argument could be set either to release namespace or omitted but multiple namespaces must be specified for role bindings creation

Environment & Versions

• Spark Operator App version: v1beta2-1.4.2-3.5.0
• Helm Chart Version: 1.2.5
• Kubernetes Version: 1.28.5
• Apache Spark version: 3.5.0

Additional context

Before #1955, it was possible to set namespace to be an empty string meaning all namespaces were watched