Fix JSON error that occurs when X-Ray config file contains NULL byte

What does this MR do and why?

We are rolling out the feature flag ai_enable_internal_repository_xray_service in #483928 (closed). It's at 25% roll out as of 2024-10-09 6:46PM PT. The feature is a new in-monolith service that scans a project's repository for dependency config files and then parses a list of libraries from the file content. This service is executed by a Sidekiq job that is triggered upon a new commit to a Duo-enabled project's default branch.

While monitoring the logs, we noticed an error occurring in one of the projects. See kibana logs: https://log.gprd.gitlab.net/app/r/s/heZdD It appears to be due to a unique case where the customer's dependency file contains an invalid byte sequence. This causes the job fail. See #483928 (comment 2150918354) for details.

The error occurs during .upsert_all where the JSON module is utilized. Since JSON doesn't support the NULL byte, it raises the following error:

This MR fixes the error above by sanitizing the file content and removing NULL bytes prior to parsing.

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Error reproduced locally with new spec test	Spec test passes after content is sanitized

Related to #483928 (closed)