Add OTLP protocol telemetry options

[loganrosen]

Summary

• Add OTLP HTTP protocol telemetry config options across Node.js, Python, Go, .NET, Java, and Rust SDKs.
• Map the new options to OTEL_EXPORTER_OTLP_PROTOCOL, OTEL_EXPORTER_OTLP_TRACES_PROTOCOL, and OTEL_EXPORTER_OTLP_METRICS_PROTOCOL when the SDK spawns the Copilot CLI.
• Document JSON/protobuf protocol selection and add focused mapping tests, including partial-config cases that ensure unset protocol env vars stay unset.

Testing

• just install
• just format
• cd java && mvn spotless:apply
• cd java && mvn verify
• cd nodejs && npm test -- --run test/telemetry.test.ts test/e2e/client_options.e2e.test.ts -t "TelemetryConfig env var mapping|should propagate process options"
• cd nodejs && npm test -- --run test/e2e/client_options.e2e.test.ts -t "should only set configured otlp protocol env vars|should propagate process options"
• cd python && uv run pytest ../python/test_telemetry.py -q
• cd python && uv run pytest ../python/e2e/test_client_options_e2e.py::TestClientOptions::test_should_propagate_process_options_to_spawned_cli -q
• cd python && uv run pytest ../python/e2e/test_client_options_e2e.py::TestClientOptions::test_should_only_set_configured_otlp_protocol_env_vars ../python/e2e/test_client_options_e2e.py::TestClientOptions::test_should_propagate_process_options_to_spawned_cli -q
• cd go && go test . && go test ./internal/e2e -run 'TestTelemetryConfigUnit|TestClientOptionsE2E'
• cd go && go test ./internal/e2e -run 'TestClientOptionsE2E/should_(only_set_configured_OTLP_protocol_env_vars|propagate_process_options_to_spawned_cli)'
• cd dotnet && dotnet test test/GitHub.Copilot.SDK.Test.csproj --filter "FullyQualifiedName~GitHub.Copilot.Test.Unit.TelemetryTests|FullyQualifiedName~Should_Propagate_Process_Options_To_Spawned_Cli"
• cd dotnet && dotnet test test/GitHub.Copilot.SDK.Test.csproj --filter "FullyQualifiedName~Should_Only_Set_Configured_Otlp_Protocol_Env_Vars|FullyQualifiedName~Should_Propagate_Process_Options_To_Spawned_Cli"
• cd rust && cargo test --features test-support --lib
• cd rust && cargo test --features test-support --lib telemetry_config && cargo test --features test-support --lib build_command

Note: full auth-dependent local E2E runs hit harness/auth isolation without GITHUB_ACTIONS=true, so validation focused on the affected telemetry mapping paths.