docs(web/docs): collapse some more indexes

There's no reason for these to not be collapsed, like other siblings.

Change-Id: Ifae2abae6733f69da642e2950a8fe5321d7becfa
Reviewed-on: https://cl.snix.dev/c/snix/+/30482
Autosubmit: Florian Klink <flokli@flokli.de>
Tested-by: besadii
Reviewed-by: edef <edef@edef.eu>

web/content/docs/components/castore/_index.md

@@ -6,5 +6,7 @@ date: 2025-04-04T16:43:14+01:00
 lastmod: 2025-04-04T16:43:14+01:00
 draft: false
 weight: 42
+sidebar:
+  collapsed: true
 ---
 

web/content/docs/reference/nix-daemon-protocol/_index.md

@@ -8,4 +8,6 @@ lastmod: 2025-03-24T13:10:37+02:00
 draft: false
 weight: 50
 toc: true
+sidebar:
+  collapsed: true
 ---

web/content/docs/reference/nix-language/_index.md

@@ -8,4 +8,6 @@ lastmod: 2025-05-01T13:10:37+02:00
 draft: false
 weight: 50
 toc: true
+sidebar:
+  collapsed: true
 ---