remove external auth docs (#17244)

Author: andrewjschuang

docs-v2/next.config.mjs

@@ -74,6 +74,12 @@ export default withNextra({
         destination: "https://pipedream.com/apps/",
         permanent: true,
       },
+      {
+        source: "/apps/connected-accounts/external-auth/",
+        destination: "/connect/",
+        permanent: true,
+      },
+
       {
         source: "/support/",
         destination: "https://pipedream.com/support/",

docs-v2/pages/apps/connected-accounts.mdx

@@ -12,8 +12,6 @@ Pipedream provides native integrations for [{process.env.PUBLIC_APPS}+ APIs](htt
 
 Pipedream handles OAuth for you, ensuring you always have a fresh access token to authorize requests, and [credentials are tightly-secured](/privacy-and-security/#third-party-oauth-grants-api-keys-and-environment-variables).
 
-If you use an existing secrets store, or manage credentials in a database, you can also [pass those to Pipedream at runtime](/apps/connected-accounts/external-auth/) instead of connecting accounts in the UI.
-
 ## Supported Apps
 
 Pipedream supports [{process.env.PUBLIC_APPS}+ apps](https://pipedream.com/apps), and we're adding more every day.
@@ -234,10 +232,6 @@ Yes, see the section on [collaborating with others](#collaborating-with-others).
 
 You can access credentials for any connected account via API, letting you build services anywhere and use Pipedream to handle auth. See [the guide for accessing credentials via API](/connect/api/#accounts) for more details.
 
-## Passing external credentials at runtime
-
-If you use a secrets store like [Pipedream Connect](/connect/) or [HashiCorp Vault](https://www.vaultproject.io/), or if you store credentials in a database, you can retrieve these secrets at runtime and pass them to any step. [See the full guide here](/apps/connected-accounts/external-auth/).
-
 ## Connecting to apps with IP restrictions
 
 <Callout type="info">