[OpenTracing.Shim] Remove obsolete constructor

[Kielek]

Cleanup for #4812

Changes

Remove obsolete constructor from OpenTracing Shim.

Merge requirement checklist

• CONTRIBUTING guidelines followed (nullable enabled, static analysis, etc.)
• [ ] Unit tests added/updated handled in previous PR.
• Appropriate CHANGELOG.md files updated for non-trivial changes
• Changes in public API reviewed (if applicable)

[codecov]

Codecov Report

Merging #4862 (135d8a9) into main (fe78453) will increase coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #4862      +/-   ##
==========================================
+ Coverage   83.91%   83.93%   +0.02%     
==========================================
  Files         293      293              
  Lines       12028    12021       -7     
==========================================
- Hits        10093    10090       -3     
+ Misses       1935     1931       -4     

Files Changed	Coverage
src/OpenTelemetry.Shims.OpenTracing/TracerShim.cs	ø

[Kielek]

Failed test OpenTelemetry.Exporter.Prometheus.Tests.PrometheusHttpListenerTests.PrometheusExporterHttpServerIntegration_NoMetrics on net462 not related to changes.

[Kielek]

@pjanotti, FYI

[pjanotti]

LGTM