chore: Fix Scala code warnings

What is the problem the feature request solves?

In https://github.com/apache/datafusion-comet/pull/2254 the profile strict-warnings introduced Build the project with strict-warnings profile enabled and need to fix scala code hygiene issues

make release PROFILES="-Pspark-3.5 -Pstrict-warnings"

Describe the potential solution

No response

Additional context

No response