Improving `dnf` Performance on RHEL 8/9 Systems

Issue

• dnf takes a long time to complete tasks like update, install, and list.
• Metadata cache generation happens every time, especially in fresh environments or after cleaning cache.
• Repository metadata is frequently re-downloaded due to short expiration settings.
• Package downloads are slow due to limited parallelism and mirror selection.
• In cloud or automated setups (e.g., CloudFormation, Chef), the delay causes timeouts or failures.
• dnf operations impact provisioning speed, affecting system readiness and automation reliability.