Install the rustls crypto provider in the handlers test setup

Building the HTTP client now relies on a process-level rustls crypto
provider being installed (we no longer pass a pre-configured TLS config
that bundled one). Tests going through TestState that didn't call
setup() — e.g. the login_sso_redirect tests — panicked when building the
client. Call setup() from from_pool_with_site_config so every TestState
installs the provider.

crates/handlers/src/test_utils.rs

@@ -170,6 +170,11 @@ impl TestState {
         pool: PgPool,
         site_config: SiteConfig,
     ) -> Result<Self, anyhow::Error> {
+        // Make sure the rustls crypto provider and tracing are set up, as
+        // building the HTTP client below requires a process-level provider to
+        // be installed.
+        setup();
+
         let workspace_root = workspace_root();
 
         let task_tracker = TaskTracker::new();