fix(tazjin/blog): Make redirects from old links permanent

Change-Id: I41d71f9aae7e64bdfef8f2b7142d13009b216eaa
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2752
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI

users/tazjin/blog/default.nix

@@ -52,8 +52,7 @@ in {
   # Generate embeddable nginx configuration for redirects from old post URLs
   oldRedirects = lib.concatStringsSep "\n" (map (post: ''
     location ~* ^(/en)?/${post.oldKey} {
-      # TODO(tazjin): 301 once this works
-      return 302 https://tazj.in/blog/${post.key};
+      return 301 https://tazj.in/blog/${post.key};
     }
   '') (filter (hasAttr "oldKey") posts));
 }