ci: fix urllib3 list index error

[emmettbutler]

This change removes an apparent programming error that caused this test failure:

    def test_distributed_tracing_apm_opt_out_true(self):                                                                                                                                                               
        """Tests distributed tracing headers are passed by default"""                                                                                                                                                  
        # Check that distributed tracing headers are passed down; raise an error rather than make the                                                                                                                  
        # request since we don't care about the response at all                                                                                                                                                        
        config.urllib3["distributed_tracing"] = True                                                                                                                                                                   
        self.tracer.enabled = False                                                                                                                                                                                    
        with mock.patch(                                                                                                                                                                                               
            "urllib3.connectionpool.HTTPConnectionPool._make_request", side_effect=ValueError                                                                                                                          
        ) as m_make_request:                                                                                                                                                                                           
            with pytest.raises(ValueError):                                                                                                                                                                            
                self.http.request("GET", URL_200)                                                                                                                                                                      
                                                                                                                                                                                                                       
            spans = self.pop_spans()                                                                                                                                                                                   
>           s = spans[0]                                                                                                                                                                                               
E           IndexError: list index out of range                                                                                                                                                                        
                                                                                                                                                                                                                       
tests/contrib/urllib3/test_urllib3.py:543: IndexError                   

Since the test looks at a span, it follows that the tracer should be enabled to generate that span.

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• The PR description articulates the motivation for the change
• The change includes tests OR the PR description describes a testing strategy
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• Newly-added code is easy to change
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• The change includes or references documentation updates if necessary
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• Reviewer has checked that all the criteria below are met
• Title is accurate
• All changes are related to the pull request's stated goal
• Avoids breaking API changes
• Testing strategy adequately addresses listed risks
• Newly-added code is easy to change
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• If necessary, author has acknowledged and discussed the performance implications of this PR as reported in the benchmarks PR comment
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[github-actions]

CODEOWNERS have been resolved as:

tests/contrib/urllib3/test_urllib3.py                                   @DataDog/apm-core-python @DataDog/apm-idm-python

[datadog-dd-trace-py-rkomorn]

Datadog Report

Branch report: emmett.butler/urllib-tracer-test
Commit report: dc0b72f
Test service: dd-trace-py

✅ 0 Failed, 87 Passed, 1468 Skipped, 3m 54.05s Total duration (35m 24.44s time saved)

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-01-07 18:37:17

Comparing candidate commit dc0b72f in PR branch emmett.butler/urllib-tracer-test with baseline commit 5f1aefc in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 394 metrics, 2 unstable metrics.

[mabdinur]

This change should address the CI failure: 86a367a.

This PR removes self.tracer.enabled = False from the test which disabled APM optout. This defeats the purpose of the test.