Revert "Docs: Set init/upgrade snippets to next on next"

This reverts commit f70e832.

docs/_snippets/init-command.md

@@ -1,11 +1,11 @@
 ```shell renderer="common" language="js" packageManager="npm"
-npx storybook@next init
+npx storybook@latest init
 ```
 
 ```shell renderer="common" language="js" packageManager="pnpm"
-pnpm dlx storybook@next init
+pnpm dlx storybook@latest init
 ```
 
 ```shell renderer="common" language="js" packageManager="yarn"
-yarn dlx storybook@next init
+yarn dlx storybook@latest init
 ```

docs/_snippets/storybook-upgrade.md

@@ -1,11 +1,11 @@
 ```shell renderer="common" language="js" packageManager="npm"
-npx storybook@next upgrade
+npx storybook@latest upgrade
 ```
 
 ```shell renderer="common" language="js" packageManager="pnpm"
-pnpm dlx storybook@next upgrade
+pnpm dlx storybook@latest upgrade
 ```
 
 ```shell renderer="common" language="js" packageManager="yarn"
-yarn dlx storybook@next upgrade
+yarn dlx storybook@latest upgrade
 ```