Updating beta banner (#6004)

## What are you changing in this pull request and why?

Based on some recent changes we've made (and may continue to make)
around versions, updating the banner to be more generic and some of the
language

## Checklist
- [ ] I have reviewed the [Content style
guide](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/content-style-guide.md)
so my content adheres to these guidelines.
- [ ] The topic I'm writing about is for specific dbt version(s) and I
have versioned it according to the [version a whole
page](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/single-sourcing-content.md#adding-a-new-version)
and/or [version a block of
content](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/single-sourcing-content.md#versioning-blocks-of-content)
guidelines.
- [ ] I have added checklist item(s) to this list for anything anything
that needs to happen before this PR is merged, such as "needs technical
review" or "change base branch."
<!--
PRE-RELEASE VERSION OF dbt (if so, uncomment):
- [ ] Add a note to the prerelease version [Migration
Guide](https://github.com/dbt-labs/docs.getdbt.com/tree/current/website/docs/docs/dbt-versions/core-upgrade)
-->
<!-- 
ADDING OR REMOVING PAGES (if so, uncomment):
- [ ] Add/remove page in `website/sidebars.js`
- [ ] Provide a unique filename for new pages
- [ ] Add an entry for deleted pages in `website/vercel.json`
- [ ] Run link testing locally with `npm run build` to update the links
that point to deleted pages
-->

---------

Co-authored-by: Leona B. Campbell <[email protected]>

Author: matthewshaver

website/src/theme/DocRoot/Layout/Main/index.js

@@ -71,7 +71,7 @@ export default function DocRootLayoutMain({
     } else {
       setPreData({
         showisPrereleaseBanner: true,
-        isPrereleaseBannerText: `You are currently viewing v${dbtVersion}, which is a prerelease of dbt Core. The latest stable version is v${latestStableRelease}`,
+        isPrereleaseBannerText: `You are viewing the docs for a prerelease version of dbt Core. There may be features described that are still in development, incomplete, or unstable.`,
       });
     }
     // If EOLDate not set for version, do not show banner