Fix Firefox disconnection issue (#1647)

Author: Killian-Aidalinfo

.changeset/heavy-hornets-switch.md

@@ -0,0 +1,5 @@
+---
+"apollo-client-devtools": patch
+---
+
+Make the background script persistent in Firefox extension to address an issue where the devtools would disconnect periodically.

src/extension/firefox/manifest.json

@@ -10,7 +10,7 @@
   },
   "page_action": {},
   "devtools_page": "devtools.html",
-  "background": { "scripts": ["background.js"], "persistent": false },
+  "background": { "scripts": ["background.js"], "persistent": true },
   "web_accessible_resources": ["panel.html", "devtools.html", "hook.js"],
   "content_scripts": [
     { "matches": ["<all_urls>"], "js": ["tab.js"], "run_at": "document_start" }