Investigate memory peak test failure

[ryanhoangt]

• Original discussion: fix: strict mimetype validation #70 (comment)
• Try: memory-profiler with the ability to monitor an individual function

[ryanhoangt]

From memory-profiler's result, it seems the increase in memory indeed doesn't come from binaryornot: https://github.com/All-Hands-AI/openhands-aci/actions/runs/13369450920/job/37334515347#step:7:185