🔒 Fix insecure deserialization vulnerability in contactMap.py

[akutuva21]

🎯 What: The vulnerability fixed
Insecure Deserialization via pickle.load in bionetgen/atomizer/contactMap.py. The code was reading potentially untrusted data from binary .dump and .dict files using the pickle module.

⚠️ Risk: The potential impact if left unfixed
The pickle module in Python is inherently unsafe. An attacker could craft a malicious binary file that, when loaded by contactMap.py, executes arbitrary code on the host machine, leading to complete system compromise or data exfiltration.

🛡️ Solution: How the fix addresses the vulnerability
Replaced the insecure pickle.load logic with the secure json.load alternative, which parses data safely without allowing arbitrary object instantiation or code execution. The file reading modes were updated from "rb" (read binary) to "r" (read text). Additionally, the mock dependencies in tests/test_contactMap.py were correctly updated to patch json.load and remove the legacy cPickle mock. (Note: As indicated by the vulnerability rationale, this migration to JSON breaks compatibility with previously generated pickle .dump files).

---

PR created automatically by Jules for task 5890336867955565148 started by @akutuva21

[google-labs-jules]

👋 Jules, reporting for duty! I'm here to lend a hand with this pull request.

When you start a review, I'll add a 👀 emoji to each comment to let you know I've read it. I'll focus on feedback directed at me and will do my best to stay out of conversations between you and other bots or reviewers to keep the noise down.

I'll push a commit with your requested changes shortly after. Please note there might be a delay between these steps, but rest assured I'm on the job!

For more direct control, you can switch me to Reactive Mode. When this mode is on, I will only act on comments where you specifically mention me with @jules. You can find this option in the Pull Request section of your global Jules UI settings. You can always switch back!

New to Jules? Learn more at jules.google/docs.

---

For security, I will only act on instructions from the user who triggered this task.