Stop tracking .device-builder.json state file

It's generated/local state from ESPHome Device Builder that changes
constantly and doesn't belong in version control.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.device-builder.json

@@ -1,5 +0,0 @@
-{
-  "_preferences": {
-    "editor_layout": "both"
-  }
-}

.gitignore

@@ -6,5 +6,4 @@
 /secrets.yaml
 /archive/
 /trash/
-.device-builder.yaml
 .device-builder.json