Fix callouts (#4593)

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

Fix callouts to be "beta" vs "public preview" on these pages:

- https://docs.getdbt.com/docs/collaborate/model-performance
- https://docs.getdbt.com/docs/collaborate/project-recommendations 

## Checklist
- [x] Review 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.
- [x] For [docs
versioning](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/single-sourcing-content.md#about-versioning),
review how to [version a whole
page](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/single-sourcing-content.md#adding-a-new-version)
and [version a block of
content](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/single-sourcing-content.md#versioning-blocks-of-content).

website/docs/docs/collaborate/model-performance.md

@@ -8,9 +8,9 @@ dbt Explorer provides metadata on dbt Cloud runs for in-depth model performance
 
 <LoomVideo id='98f33b3b7a374df0b7c04747eae6ef44' />
 
-:::tip Public preview 
+:::tip Beta 
 
-The model performance feature is now available in dbt Explorer! Check it out! 
+The model performance beta feature is now available in dbt Explorer! Check it out! 
 :::
 
 ## The Performance overview page 

website/docs/docs/collaborate/project-recommendations.md

@@ -4,9 +4,9 @@ sidebar_label: "Project recommendations"
 description: "dbt Explorer provides recommendations that you can take to improve the quality of your dbt project."
 ---
 
-:::tip Public preview 
+:::tip Beta 
 
-The project recommendations feature is now available in dbt Explorer! Check it out!
+The project recommendations beta feature is now available in dbt Explorer! Check it out!
 
 :::