fix(coderd): list templates returns non-deprecated templates by default (#17747)

## Description

Modifies the behaviour of the "list templates" API endpoints to return
non-deprecated templates by default. Users can still query for
deprecated templates by specifying the `deprecated=true` query
parameter.

**Note:** The deprecation feature is an enterprise-level feature

## Affected Endpoints
* /api/v2/organizations/{organization}/templates
* /api/v2/templates

Fixes #17565

docs/reference/api/templates.md

@@ -13,6 +13,10 @@ curl -X GET http://coder-server:8080/api/v2/organizations/{organization}/templat
 
 `GET /organizations/{organization}/templates`
 
+Returns a list of templates for the specified organization.
+By default, only non-deprecated templates are returned.
+To include deprecated templates, specify `deprecated:true` in the search query.
+
 ### Parameters
 
 | Name           | In   | Type         | Required | Description     |
@@ -739,6 +743,10 @@ curl -X GET http://coder-server:8080/api/v2/templates \
 
 `GET /templates`
 
+Returns a list of templates.
+By default, only non-deprecated templates are returned.
+To include deprecated templates, specify `deprecated:true` in the search query.
+
 ### Example responses
 
 > 200 Response