deps: bump @webqit/observer to version 3.8.19

Author: ox-harris

package-lock.json

@@ -37,10 +37,10 @@
     "astring": "^1.8.3"
   },
   "peerDependencies": {
-    "@webqit/observer": "^3.8.17"
+    "@webqit/observer": "^3.8.19"
   },
   "devDependencies": {
-    "@webqit/observer": "^3.8.17",
+    "@webqit/observer": "^3.8.19",
     "chai": "^4.3.4",
     "coveralls": "^3.1.1",
     "esbuild": "^0.14.42",