CE-922 - Update "Automated upgrades" (#1461)

## Description

Update "Automated upgrades" documentation.

## Links

Jira: [CE-922]  

Deploy previews:

## Contributor checklists

Review urgency:

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

Pull request:

- [ ] Verify that the PR is set to merge into the correct base branch
- [ ] Verify that all status checks passed
- [ ] 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)
- [ ] 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-922]:
https://hashicorp.atlassian.net/browse/CE-922?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

Author: danielehc

content/consul/v1.18.x/content/docs/enterprise/upgrades.mdx

@@ -1,7 +1,6 @@
 <EnterpriseAlert>
 
-This feature requires
-HashiCorp Cloud Platform (HCP) or self-managed Consul Enterprise.
+This feature requires Consul Enterprise.
 Refer to the [enterprise feature matrix](/consul/docs/enterprise#consul-enterprise-feature-availability) for additional information.
 
 </EnterpriseAlert>