Enable weka on models post commit workflow

[TT-billteng]

Problem description

There are references to /mnt/MLPerf in models post-commit workflow. We've held the position (so far) that no job post-commit will rely on weka as it has been very unreliable in the past.

What's changed

Let's relax this restriction for the models post-commit sub-pipeline. FAFO

Checklist

• Post commit CI passes
• Blackhole Post commit (if applicable)
• Model regression CI testing passes (if applicable)
• Device performance regression CI testing passes (if applicable)
• New/Existing tests provide coverage for changes

[tt-rkim]

FAFO BABY