What does this PR do?

Replaces the deprecated Representatives API from google.golang.org/api/civicinfo/v2 with Election API, which exists in previous versions and the current one.

Motivation

Smoke tests are failing: https://github.com/DataDog/dd-trace-go/actions/runs/14881053781/job/41789069646?pr=3482#step:7:341

=== FAIL: .  (0.00s)
FAIL	github.com/DataDog/dd-trace-go/contrib/google.golang.org/api/v2 [build failed]

=== Errors
Error: ./api_test.go:80:6: svc.Representatives undefined (type *civicinfo.Service has no field or method Representatives)

Error: ./api_test.go:134:6: svc.Representatives undefined (type *civicinfo.Service has no field or method Representatives)

Reviewer's Checklist

• Changed code has unit tests for its functionality at or near 100% coverage.
• System-Tests covering this feature have been added and enabled with the va.b.c-dev version tag.
• There is a benchmark for any new code, or changes to existing code.
• If this interacts with the agent in a new way, a system test has been added.
• New code is free of linting errors. You can check this by running golangci-lint run locally.
• Add an appropriate team label so this PR gets put in the right place for the release notes.
• Non-trivial go.mod changes, e.g. adding new modules, are reviewed by @DataDog/dd-trace-go-guild.

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