Remove legacy v2 Admin API docs (#6164)

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The newer v2 admin API docs have now reached parity with the legacy
docs, so it is safe to remove the old pages. Also adds redirects.

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Co-authored-by: Matt Shaver <[email protected]>

website/docs/docs/dbt-cloud-apis/admin-cloud-api.md

@@ -17,12 +17,6 @@ Many endpoints of the Administrative API can also be called through the [dbt Clo
 
 <div className="grid--2-col">
 
-<Card
-    title="API v2 (legacy docs)"
-    body="Our legacy API version, with limited endpoints and features. Contains information not available in v3."
-link="/dbt-cloud/api-v2-legacy"
-    icon="pencil-paper"/>
-
 <Card
     title="API v2"
     body="Our legacy API version, with limited endpoints and features. Contains information not available in v3."

website/sidebars.js

@@ -642,11 +642,6 @@ const sidebarSettings = {
           link: { type: "doc", id: "docs/dbt-cloud-apis/admin-cloud-api" },
           items: [
             "docs/dbt-cloud-apis/admin-cloud-api",
-            {
-              type: "link",
-              label: "API v2 (legacy docs)",
-              href: "/dbt-cloud/api-v2-legacy",
-            },
             {
               type: "link",
               label: "API v2",

website/vercel.json

@@ -2986,6 +2986,11 @@
       "destination": "/dbt-cloud/api-v2-legacy",
       "permanent": true
     },
+    {
+      "source": "/dbt-cloud/api-v2-legacy",
+      "destination": "/dbt-cloud/api-v2",
+      "permanent": true
+    },
     {
       "source": "/dbt-cloud/api-v4",
       "destination": "/docs/dbt-cloud-apis/admin-cloud-api",