contrib/IBM/sarama.v1: skip integration test if env variable is not set

[rarguelloF]

What does this PR do?

Skip IBM/sarama.v1 integration test if INTEGRATION env variable is not set.

Motivation

Smoke tests fail because they run the contrib tests without starting the dependent containers.

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.
• 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.
• For internal contributors, a matching PR should be created to the v2-dev branch and reviewed by @DataDog/apm-go.

Unsure? Have a question? Request a review!

[datadog-datadog-prod-us1]

Datadog Report

Branch report: rarguelloF/ibm-sarama-skip-integration-test
Commit report: 7ec5f70
Test service: dd-trace-go

✅ 0 Failed, 5174 Passed, 71 Skipped, 2m 35.45s Total Time

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-01-16 15:02:23

Comparing candidate commit c3c1801 in PR branch rarguelloF/ibm-sarama-skip-integration-test with baseline commit c27f098 in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 59 metrics, 0 unstable metrics.