Stop leaking isahc assumption (#18408)

Users of our http_client crate knew they were interacting with isahc as
they set its extensions on the request. This change adds our own
equivalents for their APIs in preparation for changing the default http
client.

Release Notes:

- N/A

crates/git_hosting_providers/src/providers/github.rs

@@ -3,7 +3,7 @@ use std::sync::{Arc, OnceLock};
 use anyhow::{bail, Context, Result};
 use async_trait::async_trait;
 use futures::AsyncReadExt;
-use http_client::{AsyncBody, HttpClient, Request};
+use http_client::{AsyncBody, HttpClient, HttpRequestExt, Request};
 use regex::Regex;
 use serde::Deserialize;
 use url::Url;
@@ -53,14 +53,16 @@ impl Github {
     ) -> Result<Option<User>> {
         let url = format!("https://api.github.com/repos/{repo_owner}/{repo}/commits/{commit}");
 
-        let mut request = Request::get(&url).header("Content-Type", "application/json");
+        let mut request = Request::get(&url)
+            .header("Content-Type", "application/json")
+            .follow_redirects(http_client::RedirectPolicy::FollowAll);
 
         if let Ok(github_token) = std::env::var("GITHUB_TOKEN") {
             request = request.header("Authorization", format!("Bearer {}", github_token));
         }
 
         let mut response = client
-            .send_with_redirect_policy(request.body(AsyncBody::default())?, true)
+            .send(request.body(AsyncBody::default())?)
             .await
             .with_context(|| format!("error fetching GitHub commit details at {:?}", url))?;