Update dogfood-policy-updater-latest-safari.sh

[allenhouchins]

This pull request improves the robustness and reliability of the .github/scripts/dogfood-policy-updater-latest-safari.sh script, focusing on more accurate parsing and updating of the Safari policy query, as well as better error handling when fetching data from external sources.

Parsing and Query Update Improvements:

• Improved extraction of the query section from the YAML response by switching from sed to a more reliable awk approach, ensuring multiline queries are correctly captured.
• Refactored the logic for updating the query section: now the new query is constructed directly within the awk command, avoiding issues with multiline variable interpolation and ensuring correct formatting and version substitution.

External Data Fetching and Error Handling:

• Enhanced error handling when fetching the latest Safari version from the SOFA feed: now checks for valid JSON responses and API error messages using jq, and validates the curl exit code before proceeding.