Removed match connectionString prefix support from EnvironmentVariablesConfigurationProvider.

[Yun-Ting]

Addressed comment:
https://github.com/open-telemetry/opentelemetry-dotnet/pull/4092/files#r1084686333

[codecov]

Codecov Report

Merging #4106 (70dcc08) into main (03af717) will increase coverage by 0.08%.
The diff coverage is 66.66%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4106      +/-   ##
==========================================
+ Coverage   85.46%   85.55%   +0.08%     
==========================================
  Files         292      293       +1     
  Lines       11306    11317      +11     
==========================================
+ Hits         9663     9682      +19     
+ Misses       1643     1635       -8     

Impacted Files	Coverage Δ
...Telemetry.Exporter.Jaeger/JaegerExporterOptions.cs	100.00% <ø> (ø)
...elemetryProtocol/Implementation/SdkLimitOptions.cs	100.00% <ø> (ø)
...orter.OpenTelemetryProtocol/OtlpExporterOptions.cs	100.00% <ø> (ø)
...Telemetry.Exporter.Zipkin/ZipkinExporterOptions.cs	100.00% <ø> (ø)
...emetry/Internal/Options/ConfigurationExtensions.cs	100.00% <ø> (ø)
...metry/Trace/BatchExportActivityProcessorOptions.cs	100.00% <ø> (ø)
...metry/Internal/Options/DelegatingOptionsFactory.cs	65.51% <65.51%> (ø)
...ables/EnvironmentVariablesConfigurationProvider.cs	80.00% <100.00%> (+16.84%)	⬆️
...p/Implementation/HttpInstrumentationEventSource.cs	72.00% <0.00%> (-4.00%)	⬇️
...ter.ZPages/Implementation/ZPagesActivityTracker.cs	100.00% <0.00%> (+2.85%)	⬆️
... and 3 more

[CodeBlanch]

LGTM