feat: Spark benchmark observability

[alanty]

What does this PR do?

increases the observability for the spark benchmark jobs:

• enable spark metrics and eventlogging on the benchmark jobs
• add a PodMonitor config to the kube-prometheus-stack to scrape the metrics
• cleanup the dockerfile to avoid a warning on build

Motivation

As we've been running benchmarks the increased visibility has helped compare performance between runs.

More

• Yes, I have tested the PR using my local account setup (Provide any test evidence report under Additional Notes)
• Mandatory for new blueprints. Yes, I have added a example to support my blueprint PR
• Mandatory for new blueprints. Yes, I have updated the website/docs or website/blog section for this feature
• Yes, I ran pre-commit run -a with this PR. Link for installing pre-commit locally

For Moderators

• E2E Test successfully complete before merge?

[vara-bonthu]

lgtm