Link to proxy doc on Learn (Azure#47241)

Author: scottaddie

sdk/core/Azure.Core/samples/Configuration.md

@@ -22,7 +22,7 @@ SecretClientOptions options = new SecretClientOptions()
 
 ## Setting a custom retry policy
 
-Using `RetryOptions` to configure retry behavior is sufficient for the vast majority of scenarios. For more advanced scenarios, it's possible to use a custom retry policy by setting the `RetryPolicy` property of client options class. This can be accomplished by implementing a retry policy that derives from the `RetryPolicy` class, or by passing in a `DelayStrategy` into the existing `RetryPolicy` constructor. The `RetryPolicy` class contains hooks to determine if a request should be retried and how long to wait before retrying. 
+Using `RetryOptions` to configure retry behavior is sufficient for the vast majority of scenarios. For more advanced scenarios, it's possible to use a custom retry policy by setting the `RetryPolicy` property of client options class. This can be accomplished by implementing a retry policy that derives from the `RetryPolicy` class, or by passing in a `DelayStrategy` into the existing `RetryPolicy` constructor. The `RetryPolicy` class contains hooks to determine if a request should be retried and how long to wait before retrying.
 
 In the following example, we implement a policy that will prevent retries from taking place if the overall processing time has exceeded a configured threshold. Notice that the policy takes in `RetryOptions` as one of the constructor parameters and passes it to the base constructor. By doing this, we are able to delegate to the base `RetryPolicy` as needed (either by explicitly invoking the base methods, or by not overriding methods that we do not need to customize) which will respect the `RetryOptions`.
 
@@ -68,7 +68,7 @@ SecretClientOptions options = new SecretClientOptions()
 };
 ```
 
-Another scenario where it may be helpful to use a custom retry policy is when you need to customize the delay behavior, but don't need to adjust the logic used to determine whether a request should be retried or not. In this case, it isn't necessary to create a custom `RetryPolicy` class - instead, you can pass in a `DelayStrategy` into the `RetryPolicy` constructor.  
+Another scenario where it may be helpful to use a custom retry policy is when you need to customize the delay behavior, but don't need to adjust the logic used to determine whether a request should be retried or not. In this case, it isn't necessary to create a custom `RetryPolicy` class - instead, you can pass in a `DelayStrategy` into the `RetryPolicy` constructor.
 
 In the below example, we create a customized delay strategy that uses a fixed sequence of delays that are iterated through as the number of retries increases. We then pass the strategy into the `RetryPolicy` constructor and set the constructed policy in our options.
 ```C# Snippet:SequentialDelayStrategy
@@ -153,7 +153,7 @@ SecretClientOptions options = new SecretClientOptions()
 ```
 
 > **_A note to library authors:_**
-Library-specific response classifiers _will_ be respected if a user sets a custom policy deriving from `RetryPolicy` as long as they call into the base `ShouldRetry` method. If a user doesn't call the base method, or sets a `HttpPipelinePolicy` in the `RetryPolicy` property, then the library-specific response classifiers _will not_ be respected. 
+Library-specific response classifiers _will_ be respected if a user sets a custom policy deriving from `RetryPolicy` as long as they call into the base `ShouldRetry` method. If a user doesn't call the base method, or sets a `HttpPipelinePolicy` in the `RetryPolicy` property, then the library-specific response classifiers _will not_ be respected.
 
 ## User provided HttpClient instance
 
@@ -168,25 +168,4 @@ SecretClientOptions options = new SecretClientOptions
 
 ## Configuring a proxy
 
-```C# Snippet:HttpClientProxyConfiguration
-using HttpClientHandler handler = new HttpClientHandler()
-{
-    Proxy = new WebProxy(new Uri("http://example.com"))
-};
-
-SecretClientOptions options = new SecretClientOptions
-{
-    Transport = new HttpClientTransport(handler)
-};
-```
-
-## Configuring a proxy using environment variables
-
-You can also configure a proxy using the following environment variables:
-
-* `HTTP_PROXY`: the proxy server used on HTTP requests.
-* `HTTPS_PROXY`: the proxy server used on HTTPS requests.
-* `ALL_PROXY`: the proxy server used on HTTP and HTTPS requests in case `HTTP_PROXY` or `HTTPS_PROXY` are not defined.
-* `NO_PROXY`: a comma-separated list of hostnames that should be excluded from proxying.
-
-**Warning:** setting these environment variables will affect every new client created within the current process.
+This guidance has moved to [Configure a proxy when using the Azure SDK for .NET](https://learn.microsoft.com/dotnet/azure/sdk/configure-proxy).

sdk/core/Azure.Core/tests/samples/ConfigurationSamples.cs

@@ -2,9 +2,7 @@
 // Licensed under the MIT License.
 
 using System;
-using System.Net;
 using System.Net.Http;
-using System.Threading.Tasks;
 using Azure.Core.Pipeline;
 using Azure.Identity;
 using Azure.Security.KeyVault.Secrets;
@@ -71,24 +69,6 @@ public void SettingHttpClient()
             #endregion
         }
 
-        [Test]
-        public void HttpClientProxyConfiguration()
-        {
-            #region Snippet:HttpClientProxyConfiguration
-
-            using HttpClientHandler handler = new HttpClientHandler()
-            {
-                Proxy = new WebProxy(new Uri("http://example.com"))
-            };
-
-            SecretClientOptions options = new SecretClientOptions
-            {
-                Transport = new HttpClientTransport(handler)
-            };
-
-            #endregion
-        }
-
         [Test]
         public void SetPollyRetryPolicy()
         {