Upgraded python version in the callback service

[Sachinbisht27]

#78

Please complete the following steps and check these boxes before filing your PR:

Types of changes

• Bug fix (a change which fixes an issue)
• New feature (a change which adds functionality)

Short description of what this resolves:

Changed the Python environment variable in the build.yml file to update the environment from 3.8 to 3.11 in the cloud function.

Checklist:

• I have performed a self-review of my own code.
• The code follows the style guidelines of this project.
• The code changes are passing the CI checks
• I have documented my code wherever required.
• The changes requires a change to the documentation.
• I have updated the documentation based on the my changes.

[vivek-kumar-pandey]

Looks fine