fix(openchallenges): specify older version of python to match pyproject

[vpchung]

Changelog

• Due to chore(schematic): remove Schematic projects and configuration #2978, update Dockerfile so that v3.11 is used to install dependencies

Preview

Before Dockerfile update

$ nx run openchallenges-data-lambda:invoke --event events/event.json

> nx run openchallenges-data-lambda:invoke --event events/event.json

> curl -X POST 'http://localhost:9000/2015-03-31/functions/function/invocations' --data @events/event.json

{"errorMessage": "Unable to import module 'app': No module named 'gspread'", "errorType": "Runtime.ImportModuleError", "requestId": "", "stackTrace": []}

After

$ nx run openchallenges-data-lambda:invoke --event events/event.json

> nx run openchallenges-data-lambda:invoke --event events/event.json

> curl -X POST 'http://localhost:9000/2015-03-31/functions/function/invocations' --data @events/event.json

{"statusCode": 200, "body": "{\"message\": \"Data successfully pulled from OC Data google sheet.\"}"}