Nomad Docs: Add anonymous policy warning to ACL overview (#1483)

## Description

- Add anonymous policy warning to 1.11, 1.10 to ACL system overview
page, Policies section. I missed porting the warning when I moved
content from tutorials to docs in 1.10. Deniz Dugan (Security) requested
this.

## Links

Jira: [CE-1094]

-
https://unified-docs-frontend-preview-kk0w9xcxy-hashicorp.vercel.app/nomad/docs/secure/acl#policies
-
https://unified-docs-frontend-preview-kk0w9xcxy-hashicorp.vercel.app/nomad/docs/v1.10.x/secure/acl#policies

## Contributor checklists

Review urgency:

- [ ] ASAP: Bug fixes, broken content, imminent releases
- [x] 3 days: Small changes, easy reviews
- [ ] 1 week: Default expectation
- [ ] Best effort: No urgency

Pull request:

- [x] Verify that the PR is set to merge into the correct base branch
- [x] Verify that all status checks passed
- [x] Verify that the preview environment deployed successfully
- [ ] Add additional reviewers if they are not part of assigned groups

Content:

- [ ] I added redirects for any moved or removed pages
- [ ] I followed the [Education style
guide](https://github.com/hashicorp/web-unified-docs/tree/main/docs/style-guide)
- [x] I looked at the local or Vercel build to make sure the content
rendered correctly

## Reviewer checklist

- [ ] This PR is set to merge into the correct base branch.
- [ ] The content does not contain technical inaccuracies.
- [ ] The content follows the Education content and style guides.
- [ ] I have verified and tested changes to instructions for end users.


[CE-1094]:
https://hashicorp.atlassian.net/browse/CE-1094?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

Author: aimeeu

content/nomad/global/partials/warn-anon-policy.mdx

@@ -0,0 +1,6 @@
+<Warning>
+
+All unauthenticated requests to Nomad receive permissions from the anonymous token. To ensure clusters remain secure, we recommend using tokens with specific policies instead of an overly permissive anonymous token.
+
+</Warning>
+

content/nomad/v1.10.x/content/docs/secure/acl/index.mdx

@@ -38,6 +38,8 @@ list jobs and view their status, while requiring authenticated requests to
 submit new jobs or modify existing jobs. By default, there is no `anonymous`
 policy set meaning all anonymous requests are denied.
 
+@include '../../../global/partials/warn-anon-policy.mdx'
+
 ## Roles
 
 Roles group one or more ACL policies into a container which can then be used to

content/nomad/v1.11.x/content/docs/secure/acl/index.mdx

@@ -38,6 +38,8 @@ list jobs and view their status, while requiring authenticated requests to
 submit new jobs or modify existing jobs. By default, there is no `anonymous`
 policy set meaning all anonymous requests are denied.
 
+@include '../../../global/partials/warn-anon-policy.mdx'
+
 ## Roles
 
 Roles group one or more ACL policies into a container which can then be used to