doc: correct tracer docs

[Flarna]

Remove context related docs from Tracer API as they are wrong since #1764.

[codecov]

Codecov Report

Merging #1901 (7701fd2) into main (83343ef) will increase coverage by 0.37%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #1901      +/-   ##
==========================================
+ Coverage   92.44%   92.81%   +0.37%     
==========================================
  Files         159      176      +17     
  Lines        5146     6080     +934     
  Branches     1089     1287     +198     
==========================================
+ Hits         4757     5643     +886     
- Misses        389      437      +48     

Impacted Files	Coverage Δ
...ry-exporter-collector/src/CollectorExporterBase.ts	92.45% <0.00%> (ø)
...ntelemetry-web/src/enums/PerformanceTimingNames.ts	100.00% <0.00%> (ø)
...rumentation/src/platform/browser/old/autoLoader.ts	100.00% <0.00%> (ø)
...ry-context-zone-peer-dep/src/ZoneContextManager.ts	85.18% <0.00%> (ø)
...ackages/opentelemetry-web/src/WebTracerProvider.ts	100.00% <0.00%> (ø)
packages/opentelemetry-web/src/types.ts	100.00% <0.00%> (ø)
...-instrumentation-fetch/src/enums/AttributeNames.ts	100.00% <0.00%> (ø)
...es/opentelemetry-context-zone-peer-dep/src/util.ts	100.00% <0.00%> (ø)
...s/opentelemetry-instrumentation-fetch/src/fetch.ts	99.23% <0.00%> (ø)
packages/opentelemetry-web/src/utils.ts	94.66% <0.00%> (ø)
... and 8 more

[johnbley]

lgtm