contrib/go-chi: Apply DD_TRACE_HTTP_SERVER_ERROR_STATUSES

[mtoffl01]

What does this PR do?

Removes isServerError function from go-chi and go-chi.v5 integrations. In the case that the contribs have not been initialized with a custom error checker via WithStatusError, they will rely on the error checker from httptrace.
This allows go-chi and go-chi.v5 integrations to be impacted by DD_TRACE_HTTP_SERVER_ERROR_STATUSES.

Motivation

Noticed the Test_Config_HttpServerErrorStatuses_FeatureFlagCustom system test was failing for go-chi (link)

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.

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[pr-commenter]

Benchmarks

Benchmark execution time: 2024-11-05 16:29:20

Comparing candidate commit 2cdd6a9 in PR branch mtoff/fix-chi-errors with baseline commit c9fc691 in branch main.

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