fix(opentelemetry): support attribute argument in TracerProvider.get_tracer() (backport #9941 to 2.9)

[mabdinur]

Resolves incompatibility introduced by:
open-telemetry/opentelemetry-python@d4e13bd.

In opentelemetry-api==1.26.0,
ddtrace.opentelemetry.TracerProvider.get_tracer(...) gets called with attributes argument
(here). This optional argument is not currently supported in ddtrace and this raises a TypeError when ddtrace-opentelemetry support is enabled.

This PR resolves this incompatibility by providing two implementations for ddtrace.opentelemetry.TracerProvider.get_tracer, one for opentelemetry-api>=1.26 and one for opentelemetry<1.26.

Checklist

• PR author has checked that all the criteria below are met
• The PR description includes an overview of the change
• The PR description articulates the motivation for the change
• The change includes tests OR the PR description describes a testing strategy
• The PR description notes risks associated with the change, if any
• Newly-added code is easy to change
• The change follows the library release note guidelines
• The change includes or references documentation updates if necessary
• Backport labels are set (if applicable)

Reviewer Checklist

• 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
• Release note makes sense to a user of the library
• If necessary, author has acknowledged and discussed the performance implications of this PR as reported in the benchmarks PR comment
• Backport labels are set in a manner that is consistent with the release branch maintenance policy

[datadog-dd-trace-py-rkomorn]

Datadog Report

Branch report: backort-9941-2_9
Commit report: b9b9801
Test service: dd-trace-py

✅ 0 Failed, 174253 Passed, 1486 Skipped, 11h 21m 37.27s Total duration (1m 54.67s time saved)

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 8 lines in your changes missing coverage. Please review.

Project coverage is 10.11%. Comparing base (ed53e56) to head (b9b9801).

Files	Patch %	Lines
ddtrace/opentelemetry/_trace.py	0.00%	8 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##              2.9    #9963       +/-   ##
===========================================
- Coverage   71.47%   10.11%   -61.36%     
===========================================
  Files        1289     1258       -31     
  Lines      122525   120703     -1822     
===========================================
- Hits        87571    12215    -75356     
- Misses      34954   108488    +73534     

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