cli: deprecate plugin:diff command

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

.changeset/clever-turtles-work.md

@@ -0,0 +1,5 @@
+---
+'@backstage/cli': patch
+---
+
+Deprecated the `plugin:diff` command. If you wish to keep running similar checks in your project we recommend using bespoke scripts. A useful utility for such scripts is `@manypkg/get-packages`, which helps you enumerate all packages in a monorepo.

packages/cli/cli-report.md

@@ -13,7 +13,6 @@ Options:
 
 Commands:
   new [options]
-  plugin:diff [options]
   test
   config:docs [options]
   config:print [options]
@@ -379,17 +378,6 @@ Options:
   --watchman
 ```
 
-### `backstage-cli plugin:diff`
-
-```
-Usage: backstage-cli plugin:diff [options]
-
-Options:
-  --check
-  --yes
-  -h, --help
-```
-
 ### `backstage-cli repo`
 
 ```

packages/cli/src/commands/index.ts

@@ -260,10 +260,12 @@ export function registerCommands(program: Command) {
     );
 
   program
-    .command('plugin:diff')
+    .command('plugin:diff', { hidden: true })
     .option('--check', 'Fail if changes are required')
     .option('--yes', 'Apply all changes')
-    .description('Diff an existing plugin with the creation template')
+    .description(
+      'Diff an existing plugin with the creation template [DEPRECATED]',
+    )
     .action(lazy(() => import('./plugin/diff').then(m => m.default)));
 
   // TODO(Rugvip): Deprecate in favor of package variant