fix: Configures the vars for communication between app and sidecar for otel

[blainsmith]

What I'm changing

1. Added OTEL_EXPORTER_OTLP_PROTOCOL: "grpc"
   • This tells the Rust application to use the gRPC exporter instead of defaulting to stdout
   • The application will now send traces to the ADOT sidecar
2. Added port mappings to the ADOT sidecar
   - Explicitly maps port 4317 for the ADOT collector
   - Ensures the gRPC endpoint is properly accessible within the task

How I did it

• The source-data-proxy application will now export traces via gRPC to localhost:4317
• The ADOT sidecar listening on port 4317 will receive these traces
• The ADOT collector will batch and forward them to AWS X-Ray
• You'll be able to see traces in CloudWatch/X-Ray

How to test it

After deploying this change, your traces should start flowing to X-Ray. You can verify by checking the ADOT container logs at /ecs/{stack-name}-adot and looking for trace export activity.

PR Checklist

• This PR has no breaking changes.
• I have updated or added new tests to cover the changes in this PR.
• This PR affects the Source Cooperative Frontend & API,
  and I have opened issue/PR #XXX to track the change.

[alukach]

Merging to feat/otel so that we can deploy to staging via Github Actions.

[alukach]

I'm uncertain if the usage of localhost within the a Fargate cluster works, but let's try and see.