chore: remove depreacted opencensus instrumentation

[tim-mwangi]

Description

Opencensus go sdk has been deprecated and archived. https://github.com/census-ecosystem/opencensus-go-exporter-zipkin . Since it is not actively used we will remove it from the agent.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 60.27%. Comparing base (1fd91b9) to head (7ddaacd).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #242      +/-   ##
==========================================
+ Coverage   59.37%   60.27%   +0.90%     
==========================================
  Files          72       59      -13     
  Lines        2895     2646     -249     
==========================================
- Hits         1719     1595     -124     
+ Misses       1095      973     -122     
+ Partials       81       78       -3     

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