fix: Remove patch constraint on Zipkin exporter (#1870)

Author: kaylareopelle

sdk/opentelemetry-sdk.gemspec

@@ -38,7 +38,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'bundler', '>= 1.17'
   spec.add_development_dependency 'faraday', '~> 0.13'
   spec.add_development_dependency 'minitest', '~> 5.0'
-  spec.add_development_dependency 'opentelemetry-exporter-zipkin', '~> 0.19.0'
+  spec.add_development_dependency 'opentelemetry-exporter-zipkin', '~> 0.19'
   spec.add_development_dependency 'opentelemetry-instrumentation-base', '~> 0.20'
   spec.add_development_dependency 'opentelemetry-test-helpers'
   spec.add_development_dependency 'pry'