[release-1.19] fix: reuse global TracerProvider to avoid memory leak

[k8s-infra-cherrypick-robot]

This is an automated cherry-pick of #5540

/assign nojnhuh

fixes potential OOM due to tracing (even if tracing not enabled)

[codecov]

Codecov Report

Attention: Patch coverage is 66.66667% with 2 lines in your changes missing coverage. Please review.

Project coverage is 52.54%. Comparing base (1c994c5) to head (a2c3b6d).
Report is 3 commits behind head on release-1.19.

Files with missing lines	Patch %	Lines
pkg/ot/traces.go	0.00%	2 Missing ⚠️

Additional details and impacted files

@@               Coverage Diff                @@
##           release-1.19    #5545      +/-   ##
================================================
- Coverage         52.61%   52.54%   -0.07%     
================================================
  Files               272      272              
  Lines             29485    29474      -11     
================================================
- Hits              15513    15488      -25     
- Misses            13165    13184      +19     
+ Partials            807      802       -5     

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[nojnhuh]

/kind bug
/lgtm
/approve

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: 81b57112ccc8275a52dcbf34f86ea98660be4466

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: nojnhuh

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